He told MPs earlier in the Commons: "We welcome the opportunity of a general election because it gives the British people the chance to vote for a Labour government that will put the interests of the majority first".
Parliament will be dissolved on May 2.
May said it was "only recently and reluctantly" that she had made a decision to call for a snap election, rather than serve a fixed term until 2020 under what is a slim Tory majority. The election would enable the parties to "make our respective cases to the country and then to respect the result and the mandate it provides to give Britain the strongest possible hand in the negotiations to come".
But her decision also opens the door to more uncertainty in the region, as it now puts Europe's three most powerful nations - Britain, Germany and France - into full-throttle election mode. A national election in May 2015 was followed by the June 2016 referendum on European Union membership.
Liberal Democrat leader Tim Farron accused May of putting her party above the country and said she was running scared by not accepting the challenge of TV debates.
Under the Fixed-term Parliaments Act passed by the coalition government, May had to win the backing two thirds of MPs to bring the date of the 2020 election forward to this year.
Theresa May told the BBC in an interview on Wednesday that an early election is in the national interest because it will strengthen the country's position in negotiations to leave the European Union.
Addressing MPs beforehand, May said an early vote would strengthen her hand in dealing both with Brussels and domestic critics seeking to "frustrate the process" of Brexit.
She has categorically denied the June 8 poll will be a sort of re-run of last year's referendum, saying there could be no "turning back" on the Brexit decision but if she was re-elected, it would be a vote of confidence in her government's central goals of gaining "control" of the UK's laws, borders and money.
The president of the European Commission, Mr Jean-Claude Juncker, believes "real" Brexit talks will only start after British snap elections, an EU spokesman said yesterday.
UKIP leader Paul Nuttall accused May of putting party politics ahead of the national interest - but the party now does not have any MPs in the House of Commons. Opinion polls give them a big lead over the Labour opposition, and May is gambling that an election will deliver her a personal mandate from voters and produce a bigger Conservative majority in Parliament.
By contrast, Labour has struggled to form a strategy over Brexit, while Corbyn's left-wing leadership is opposed by many of his more centrist MPs.
"We welcome the general election but this is a prime minister who promised there wouldn't be one, a prime minister who can not be trusted", he told the Commons on Wednesday.
But May won the day with a commanding majority. It is a two-edged sword and the stakes are high but May has shown she is prepared to be bold and decisive.