The Prime Minister was the only leader of a major political party not to take part in Wednesday night’s debate, after Labour leader Jeremy Corbyn surprisingly announced he would be attending hours before it started.
Liberal Democrat leader Tim Farron started his opening statement by suggesting the Tory leader might be outside someone’s house “sizing it up” to pay for social care – prompting laughs from the audience.
The hashtag #whereisTheresa soon started trending on Twitter, as users began sharing memes and pictures mocking the Prime Minister.
Mr Farron said: “Where do you think Theresa May is tonight? Take a look out your window? She might be out there sizing up your house to pay for your social care.
“And why do you think she called this election? She wants five years as Prime Minister and she think you’ll give to her no questions asked – literally.”
Mrs May was openly criticised by rival leaders during the debate, with Home Secretary Amber Rudd taking to the podium to represent the Conservatives.
Jeremy Corbyn told audiences members “tonight I am here” as he launched a savage attack on the Conservative Party’s policies on social care and taxation.
He had announced in a speech in Reading earlier on Wednesday: “There’s a debate in Cambridge tonight. I invite her to go to Cambridge to debate her record… and let the public make up their mind.”
The Labour leader had previously ruled out attending if Mrs May refused to take part.
Mr Corbyn was joined by Mr Farron, Ms Rudd, UKIP’s Paul Nuttall, SNP deputy leader Angus Robertson, Green co-leader Caroline Lucas and Plaid Cymru leader Leanne Wood for the debate.
The leaders battled it out over the Brexit negotiations, cuts to public services and immigration as voters prepare to take to the polls next week.
Earlier on Wednesday, the Prime Minister denied she was “frightened” taking on her rivals in a head-to head-debate.
While on the campaign trail in Bath, Mrs May said: “I think debates where the politicians are squabbling amongst themselves doesn’t do anything for the process of electioneering.”
Ahead of the broadcast Mr Corbyn said the PM’s refusal to take part was a “sign of weakness” but Mrs May said she wanted to speak directly to voters and answer their questions rather than “squabbling” with other party leaders.
The Conservative leader was largely mocked for her performance during a Channel 4/Sky News election special on Monday night.