Labour has vowed there will be "no pacts" with the Liberal Democrats or the SNP at the next election as panicking Tories accused opposition parties of secret alliances.
Shadow Foreign Secretary David Lammy said he sees "no possibility" of Labour making a formal alliance with the Liberal Democrats and argued that voters don't want "politicians to stitch up deals in the corridors of power".
Conservatives have tried to shift blame for their double by-election defeat onto opposition parties, with Health Secretary Sajid Javid urging Keir Starmer and Ed Davey to "come clean" about electoral pacts.
But Mr Lammy insisted there were no deals - and said Labour would form the next Government "outright"
It comes as Boris Johnson claimed he was “thinking actively” about a third term in office that would last until the “mid-2030s”.
The Prime Minister has travelled to Germany for the G7 summit but his diplomatic efforts are being overshadowed by mounting domestic woes
Mr Lammy told Sky News: "People expect to make their own judgment and decide who they want to vote for.
"In the end, in the 22 years that I've been in public life, it's clear to me that we have two major political parties - those political parties actually a coalition in of themselves - and for the Labour Party to form the next government we have to pick up votes from people who are considering voting Conservative.
"That's the basis on which will form the next government.
"I see no possibility of us forming the next government by picking up a few Lib Dem votes. I've got to be honest about - or indeed Green votes - and that is why I'm really pleased about what happened in Wakefield on Thursday."
Asked if Labour was ready for an alliance with the SNP, he said Labour would not be striking any deals but wanted to win the next general election "outright".
He added: "We've absolutely clear there is no, we're not striking deals with the SNP or the Liberal Democrats, we want to win outright, and we will be fighting for every single vote in every single constituency, right across the country."
Liberal Democrat leader Sir Ed Davey said his party won a stunning victory in Tiverton and Honiton because it picked up Tory votes.
"It would've been impossible to win that seat if we hadn't persuaded former Conservatives to vote for us, and they did in their droves," he told BBC's Sunday Morning.
Asked if there was a deal with Labour, he said: "No not at all because if you look at the seats we need to win at the next election, which we can win at the next election, we have got to persuade a lot of former Conservatives to vote for us and that's what we are doing very, very successfully."
Sir Ed said it was clear voters had "worked out for themselves who they need to get behind if they want to punish Boris Johnson and the Conservatives".
