Theresa May has accused Jeremy Corbyn, Tim Farron and Nicola Sturgeon of seeking to “unite together to divide our country”.
Amid claims she is trying to “crush” parliamentary debate by calling an early election, the prime minister insisted it was “right” to have proper scrutiny and for arguments to be challenged.
But she said it was clear the SNP and others wanted to use the Commons to “frustrate” the Brexit process.
Speaking at Prime Minster’s Questions, she added: “I will be asking the British people for a mandate to complete Brexit and to make a success of it.
“What do we know that the leader of the Labour party, the leader of the Liberal Democrats and the leader of the Scottish nationalists have in common?
“Corbyn, Farron and Sturgeon want to unite together to divide our country, and we will not let them do it.
“Every vote for the Conservatives will make it harder for those who want to stop me getting the job done.
“Every vote for the Conservatives will make me stronger when I negotiate for Britain with the European Union.”
SNP Westminster Leader Angus Robertson told Mrs May most people realised she had taken the decision “because of the woeful state of the Labour party”.
And he said he looked forward to a “straight fight” between his party and the Conservatives in the coming weeks.
Suggesting she was “running scared” of the TV debates, he added: “If the prime minister is so confident that her hard Brexit, pro-austerity, anti-immigration case is right, she should debate it with opposition leaders during the campaign.”
The Tory leader said she planned to take the debate to “every part of the UK”.
She also said – in an awkward choice of phrase having told the SNP “now is not the time” for a second referendum – “now is the time” for the party to put aside its “tunnel vision” on the subject and get “back to the day job”.
Mr Corbyn welcomed the general election, but said the prime minister could not be trusted after ruling one out.
Also attacking her on the issue of the TV debates, he added: “You say that it is about leadership, yet you refuse to defend your record.”
Mr Farron said the election could change the direction of the country and that the public deserved to hear the party leaders set out their plans and debate them publicly.
During the weekly exchange, Mrs May faced cries of “frit” from Labour backbenchers.