Twitter has accused the Conservatives of misleading the public after they rebranded one of their official party accounts to make it look like a factchecking service during the ITV leaders’ debate.

The party was widely criticised on Tuesday night when it temporarily changed the name of its Conservative campaign headquarters press office Twitter account, which is followed by nearly 76,000 users, to factcheckUK from its usual CCHQPress.

The account’s avatar was switched during the debate from the party’s logo to a white tick against a purple background, and the account was used to promote pro-Tory statements prefixed with the word “FACT”. Shortly after the debate finished, the Twitter account name was changed back to CCHQ Press.

On Wednesday morning, the foreign secretary, Dominic Raab, defended the move and told BBC Breakfast that “no one gives a toss about the social media cut and thrust”.

Picture 587 Photograph: Conservative rebranding FACTCHECK

In a statement, Twitter said the Conservatives had misled the public and it would take “decisive corrective action” if a similar stunt was attempted again. “Twitter is committed to facilitating healthy debate throughout the UK general election,” said a spokesperson.

“We have global rules in place that prohibit behaviour that can mislead people, including those with verified accounts. Any further attempts to mislead people by editing verified profile information – in a manner seen during the UK election debate – will result in decisive corrective action.”

Q&A How did the Tories pretend to be a factchecking service? Show Hide During the ITV live leaders debate on 19 November, the Conservative party re-branded their press office account on Twitter as 'factcheckUK', to tweet anti-Corbyn points during the programme to its 75,000 followers. On Twitter accounts there is a username - in this case @CCHQpress - and a screen name, which appears more prominently. The Conservatives changed the screen name to 'factcheckUK', and also changed the logo and biography of the account to read 'fact checking Labour from CCHQ'. No explicit mention of the Conservative party name in full was made, so users would have to know that CCHQ is an acronym for 'Conservative campaign headquarters' in order to understand who was providing the fake fact-checking service. Because the @CCHQPress account on Twitter is 'verified', it means when it appears it has a blue check mark next to the name, to show that Twitter has 'verified' that the account is who it says it is. This was retained while the account was tweeting under the false name 'factcheckUK'. Martin Belam

The Conservatives’ tactic was immediately criticised by the established factchecking website Full Fact, which is run by a charity. The organisation said the party’s account should not be allowed to be used in this way while verified and that it had complained to Twitter.

“It is inappropriate and misleading for the Conservative press office to rename their Twitter account factcheckUK during this debate. Please do not mistake it for an independent factchecking service,” it said.

The Labour MP David Lammy called on the Electoral Commission to investigate and punish what he called “a blatant attempt to deceive the public”.

“The Conservative party press office CCHQPress rebranding themselves as ’factcheckUK shows what disdain this party and this government has for the truth,” he said.

In a statement, the commission said: “Voters are entitled to transparency and integrity from campaigners in the lead-up to an election, so they have the information they need to decide for themselves how to vote.

“While we do not have a role in regulating election campaign content, we repeat our call to all campaigners to undertake their vital role responsibly and to support campaigning transparency.”

The Liberal Democrat education spokesperson, Layla Moran, told BBC Radio 4’s Today programme that people could easily have mistaken the Conservative Twitter account for an independent factchecker. She said she had previously found herself taken in by fake accounts.

“Twitter is fast-moving. You’re looking quickly at your feed. You tend to look at the name rather than scrutinise the handle,” she said. Moran said she had reported the account as soon as she saw it and that it should be referred to the Electoral Commission.

On BBC Breakfast, Raab said he thought it had been very clear that the account was run by the Conservatives.

“We’ve had all sorts of nonsense thrown at the Conservatives. We’re going to be in the process – one of the things we learned from the last election – of having a really good instant rebuttal of the nonsense,” he said.

Play Video 1:00 Dominic Raab: Tory Twitter name change was 'instant rebuttal to Labour nonsense' - video

Will Moy, the chief executive of Full Fact, said Twitter should have acted sooner and could have forcibly renamed the account.

“It was an attempt to mislead voters and I think it is inappropriate and misleading for a serious political party to behave that way,” he said. “And it’s surprising as well. Why would a self-respecting political party choose to impersonate something else to put its campaign messages out there?” he said on Radio 4.

Speaking on the BBC’s Newsnight on Tuesday night after the leaders’ debate, the Conservative party chairman, James Cleverly, said the nature of the Twitter account was clear because its handle remained CCHQPress.

Asked whose idea it had been to change the account, he said: “The digital team have a remit. I set that remit, they work within that remit. I’m absolutely comfortable with them calling out when the Labour party put what they know to be complete fabrications in the public domain. And we will call them out every time they do it.”