Labour leader Jeremy Corbyn has welcomed the prime minister's election announcement, calling it a "chance to vote for a government that will put the interests of the majority first".
Mr Corbyn said the Tories had "failed to rebuild the economy" and that he would be campaigning on housing, education and the NHS.
Theresa May says she wants a general election to take place on 8 June.
MPs will vote on Wednesday to approve her plan.
Explaining her decision to hold the vote, Theresa May said Britain needed certainty, stability and strong leadership following the EU referendum.
Asked whether he was the next prime minister, Mr Corbyn added: "If we win the election, yes - and I want to lead a government that will transform this country, give real hope to everybody, and above all bring about a principle of justice for everybody and economic opportunities for everybody."
The Labour leader, who was elected to replace Ed Miliband after Labour lost the 2015 election, said this time the party would be challenging the "economic narrative" that requires "huge cuts" to pay for the banking crisis.
Mr Corbyn also said Labour had been setting out policies offering a "clear and credible choice for the country", adding: "We look forward to showing how Labour will stand up for the people of Britain."
Labour's shadow cabinet met in the aftermath of Mrs May's announcement.
Former home secretary Alan Johnson said he would not be seeking re-election in the Hull West and Hessle seat he has represented since 1997.
And Tom Blenkinsop, who has been MP for Middlesbrough South and East Cleveland since 2010, said he would not be standing for re-election, citing "irreconcilable differences" with the party's leadership.