Jeremy Corbyn is the latest party leader to be accused of "running scared" of TV general election debates. The row comes after a senior Labour source told reporters that the left-winger would turn down such programmes unless Prime Minister Theresa May takes part.
"Our democracy deserves better than this," said Green co-leader Caroline Lucas MP. "Theresa May should commit to doing the TV debates, and Jeremy Corbyn shouldn't be afraid to 'empty chair' the Prime Minister and debate with the other parties.
"A failure by both Corbyn and May to appear in the television debates would be a dereliction of their duty as party leaders."
First Minister of Scotland Nicola Sturgeon also attacked Corbyn over the decision, announced after Prime Minister's Questions on Wednesday 26 April.
"Faced with an open goal, Corbyn decides against even attempting to score," the SNP leader said.
Liberal Democrat leader Tim Farron added: "Given he has been absent since the day he was elected as leader of the opposition, it is no surprise that he is choosing to be absent now. The broadcasters are going to have to dust off two empty chairs, the debates must go ahead."
The 2010 and 2015 general election campaigns saw TV debates on the main broadcasters, but Downing Street has suggested that May will avoid the events and focus on the campaign trail.
However, ITV is expected to host a debate with Julie Etchingham as chair, with more details coming in early May. "ITV will hold a leaders' debate as we did in 2010 and 2015," a spokesperson for the broadcaster said.
More than 400,000 people have signed a Change.Org petition urging May to take part.