A Conservative party source suggested in the wake of the row Channel 4’s broadcasting license could be reviewed if the Conservatives were re-elected.
The Prime Minister had been invited to attend the live discussion alongside other party leaders, but had declined.
His offer to send cabinet minister Michael Gove in his place was rejected by Channel 4, which said the debate was only for party leaders.
Instead, two globe-shaped ice sculptures were displayed alongside the other politicians to represent the PM and Brexit Party leader Nigel Farage, who also refused to attend.
The event went ahead and featured Labour’s Jeremy Corbyn, Lib Dem’s Jo Swinson, the SNP’s Nicola Sturgeon, the Green Party’s Sîan Berry and Plaid Cymru’s Adam Price.
The Tories have now accused Channel 4 of “[conspiring] with Jeremy Corbyn to block the Conservatives” after it emerged that the Labour leader vetoed the decision to let Michael Gove attend the debate.
A party spokesperson said: “Under this Government the UK was the first advanced economy in the world to legislate for a net zero target and we’ve reduced emissions faster than any other advanced economy while continuing to grow our economy.”
“Broadcasters have important responsibilities to present a balanced debate representing all parties, and Michael Gove was well qualified to represent the Conservative position at this evening’s debate.”
Prior to the start of the debate, a letter of complaint was sent to Ofcom on behalf of the Conservatives which dubbed the ice sculptures a “provocative partisan stunt” and accused the broadcaster of “a pattern of bias”.
The party has also threatened to pull their license, with a party source telling BuzzFeed News the Government could “review Channel 4’s Public Services Broadcasting obligations” if they win next month’s snap election.
The source said: “Broadcasting organisations are rightly held to a higher standard — and particularly Channel 4 which has a special role enshrined in legislation.
“Any review would of course look at whether its remit should be better focused so it is serving the public in the best way possible.”
But Labour’s shadow Treasury minister, Clive Lewis, accused the PM of being “a coward and a bully” over the threats.
He said: “[Boris Johnson] thinks he is born to rule and is so used to getting his own way that he turns nasty when anyone dares challenge him.
“Britain deserves a Prime Minister that has enough of a backbone to face up to scrutiny.”