Sir Keir Starmer boasted of ‘phenomenal results’ and crowed Labour are ‘redrawing the political map’ ahead of the looming general election.
His party overtuned huge Tory majorities in both constituencies, which will prompt a fresh wave of angst among Conservative ranks.
The Prime Minister will be informed of the by-election results as he continues his trip to the Middle East in the wake of the Hamas terror attacks in Israel.
Labour gained the Mid Bedfordshire seat with a 20.5 percentage point swing toards them away from the Tories since the 2019 general election.
The result represents the largest Tory majority (24,664) overturned by Labour at a by-election since 1945.
Sir Keir said: ‘These are phenomenal results that show Labour is back in the service of working people and redrawing the political map.
‘Winning in these Tory strongholds shows that people overwhelmingly want change and they’re ready to put their faith in our changed Labour Party to deliver it.
‘Voters across Mid Bedfordshire, Tamworth and Britain want a Labour government determined to deliver for working people, with a proper plan to rebuild our country.
‘To those who have given us their trust, and those considering doing so, Labour will spend every day acting in your interests and focused on your priorities. Labour will give Britain its future back.’
Victory for Labour in Brexit-backing Tamworth saw the party overturn the Tories‘ 19,600-vote majority from the 2019 general election.
The swing from the Tories to Labour was 23.9 percentage points, which is the second-largest managed by Labour at a by-election since 1945.
It also beat the 23.7 percentage point swing that Labour achieved when winning the Selby and Ainsty by-election in July.
The Tamworth contest was triggered by the resignation of former Tory deputy chief whip Chris Pincher after he was found to have drunkenly groped two men in a posh London club.
The Mid Bedfordshire by-election was prompted by Tory ex-Cabinet minister Nadine Dorries quitting the House of Commons after a peerage row.
The turnout in Tamworth was 35.9 per cent, while the turnout in the Mid Bedfordshire by-election was 44 per cent.
Sarah Edwards, the victorious Labour candidate who secured a last-minute endorsement from TV’s Ross Kemp on polling day, said voters in Tamworth had chosen a ‘fresh start’
Labour sources pointed to how Tamworth is not among the party’s target seats for the general election and is the 57th safest Tory constituency in the country.
They also noted how the result saw a bigger swing to Labour than the South East Staffordshire by-election in 1996, which preceded Tony Blair’s landslide general election victory the next year.
A Conservative spokesman acknowledged a ‘difficult result’ in Tamworth but pointed to a ‘much-reduced turnout’ in the by-election of 35.9 per cent, compared to the larger number of voters at the last general election.
The spokesman added: ‘It’s important to see it in context. The government of the day rarely wins by-elections and there were specific reasons around the nature of the departure of the previous MP.’
Sarah Edwards, the victorious Labour candidate who secured a last-minute endorsement from TV’s Ross Kemp on polling day, said voters in Tamworth had chosen a ‘fresh start’.
‘They’ve sent a clear message to Rishi Sunak and the Conservatives that they have had enough of this failed Government, which has crashed the economy and destroyed our public services,’ she added.
‘The people of Tamworth have made it clear. It’s time for change.’
Labour are also tipped for victory in Mid Bedfordshire with the Liberal Democrats claiming their success in winning over voters in ‘true blue’ villages in the constituency has handed victory to Sir Keir’s party.
A source said: ‘We think we’ve doubled our share of the vote, and taken enough Conservative votes in the villages to help Labour get over the line.
‘It’s not the progressive vote that split tonight, it’s the Conservative vote as thousands of lifelong Tories switched to the Lib Dems.’
The Lib Dems had been eyeing victory in Mid Bedfordshire themselves but an insider noted how Labour’s vote had hardened up in the constituency’s towns during Thursday.
Labour shadow cabinet minister Peter Kyle, who has masterminded his party’s campaign in Mid Bedfordshire, told Sky News: ‘Clearly we’ve done very well in this by-election.’
Labour candidate Sarah Edwards arrives for the Tamworth by-election count at The Rawlett School
Vote counting gets underway in the Tamworth by-election as Rishi Sunak faces a huge test in the Staffordshire constituency
The Prime Minister is enduring an anxious wait to see if he’ll suffer further demoralising by-election losses
Ballot boxes were delivered to the Tamworth count at The Rawlett School in unusual style
The first ballot boxes are delivered as the count gets underway in Shefford in the Mid Bedfordshire contest
Polls closed at 10pm in contests in Tamworth and Mid Bedfordshire (where a dog was pictured waiting while its owner cast their ballot in Flitwick) after voters were asked to elect new MPs
The by-election results will be known in the early hours, with Mr Sunak set to be told the news while continuing a Middle East trip after talks with Saudi Arabia’s Mohammed bin Salman
Since becoming PM, Mr Sunak has already suffered crushing defeats in by-elections in Selby and Ainsty, and Somerton and Frome.
Both of those were previously Tory strongholds before being won by Labour and the Liberal Democrats, respectively, in July.
The Mid Bedfordshire by-election was prompted by the resignation of Tory ex-Cabinet minister Nadine Dorries from the House of Commons after a peerage row.
As polls closed in both contests last night, a Conservative spokesman was downcast about the party’s chances of clinging on to the two constituencies being contested.
‘These were always going to be challenging by-elections and the rule of thumb is that governments don’t win them,’ they said.
‘We have seen little to no enthusiasm for Sir Keir Starmer who voters can see stands for nothing and always puts short term political gain first.
‘It is clear that we have to maintain our focus on people’s immediate priorities whilst taking long-term decisions which will lead to the change this country needs.’
Labour MP Pat McFadden, his party’s national campaign coordinator, also attempted to manage expectations of success.
‘We have known all along that winning these seats would be a long shot, with huge majorities to overturn,’ he said.
‘The fact that we are even on the pitch is a sign of how far the Labour Party has changed.
‘We are making real progress in all corners of our country and showing that with Labour, we can get Britain’s future back.’
Lib Dem MP Christine Jardine played down her party’s chances of victory in Mid Bedfordshire but suggested they had won over disgruntled Tory supporters.
‘Whatever the outcome, it is clear that the Lib Dem vote has surged in true blue villages across Bedfordshire, as former lifelong Conservative voters choose to send this government a message,’ she said.
There are Tory hopes that the Lib Dem challenge in Mid Bedfordshire will bleed votes away from Labour and allow the Conservatives to hold the constituency
Labour’s campaign in Tamworth was boosted on Thursday by a last-minute endorsement for their candidate Sarah Edwards from TV’s Ross Kemp
Labour are currently around 20 points ahead of the Tories in national opinion polls, as Sir Keir seeks to put himself on course for Downing Street at a general election expected next year.
But the Opposition had sought to downplay their chances of winning the by-election contests and insisted it is a ‘moonshot’ to achieve victory in either or both seats.
A spokesman for Sir Keir this week described them as ‘super safe’ constituencies for the Tories ahead of the by-election contests.
‘These are in super safe Tory seats that would require for us to overturn results larger than those which we overturned in Selby,’ the spokesman said.
‘If we were to win Tamworth and had that swing at a general election, it would mean that the Tories will be down to fewer than 60 seats at the next general election.
‘So a little bit of perspective is required here. Tamworth is a seat where the Tories got 66 per cent of the vote at the last election. Mid Bedfordshire is a similarly safe Tory constituency.’
The best chance for the Lib Dems of springing an upset was likely to be in Mid Bedfordshire, where they began campaigning even before Ms Dorries officially quit.
There were Tory hopes that the Lib Dem challenge in Mid Bedfordshire – where they came second in the 2005 and 2010 general elections – would bleed votes away from Labour and allow the Conservatives to hold the constituency.
But a Tory source told MailOnline that Labour had sidelined the Lib Dems as the campaign had gone on, and Sir Ed Davey’s party had since been targeting blue areas.
The by-election contests have been bad-tempered in both seats, with attacks on the Tory candidate in Tamworth for suggesting in an old social media post that families using food banks should ‘f*** off’ if they could afford TVs and phones.
Mr Sunak this week declined to condemn an apparent suggestion by Andrew Cooper that out-of-work parents who cannot afford to feed their children should ‘f*** off’.
The Tory leader was asked during Prime Minister’s Questions about a photo of a flowchart shared by Mr Cooper on Facebook.
The diagram suggested that those who are out of work, pay for ‘TV Sky/BT/etc’, or ‘have a phone contract + £30’ should ‘f*** off’ rather than seek help.
In reply to the question, the PM said only that he was ‘proud of our record supporting people with the cost of living’, before outlining Government policies aimed at supporting people through the crisis.
Mr Cooper told Channel 5 News he was ‘sorry if I’ve offended somebody’ after the post was publicised.
Asked if regretted sharing the image, he said: ‘Obviously it is not something I would share now in today’s world.
‘We obviously mature and have different opinions than we do three years ago.’
He added: ‘Of course I’m sorry if I’ve offended somebody. But it is very hard in today’s world to have an opinion and not to offend somebody.’
Labour’s campaign in Tamworth was boosted on Thursday by a last-minute endorsement from TV’s Ross Kemp.
‘It’s gonna be close,’ the former EastEnders actor told voters in a social media video.
‘But you have the opportunity to vote for a difference in your constituency today. So please vote for Sarah Edwards.’
In Mid Bedfordshire, Labour last month threatened legal action against the Lib Dems as the two parties clashed over claims made on campaign leaflets.
Labour’s candidate in Mid Bedfordshire, Alistair Strathern, previously made headlines after he was unmasked as an eco-activist who posed as a zombie during a Greenpeace protest outside the Home Office in November last year.
The PM’s press secretary this week told reporters that ‘mid-term by-elections are extremely tough for incumbent governments’ but said the Tories were ‘fighting for every vote’ in the by-elections.
The Tories have held Mid Bedfordshire since 1931 and Ms Dorries held on to it in 2019 by 24,664 votes over second-placed Labour.