The Fixed Term Parliaments Act, brought in after the Coalition government was formed in 2010, means Mrs May must win the backing of two-thirds of MPs to bring an election forward from 2020.
Theresa May has said a snap general election is necessary to prevent opposition parties at Westminster "frustrating" the Brexit process.
"When all is said and done, she has chosen this election, she presumably has some confidence in her position, why won't she go out there and argue with people like me who want to challenge her?"
"It was with reluctance that I decided the country needs this election, but it is with strong conviction that I say it is necessary to secure the strong and stable leadership the country needs to see us through Brexit and beyond." she said.
The prime minister did give some hints about how long she expected a Brexit deal to take.
"Had the election been in 2020, we would have been coming up to the most crucial part of the negotiations at the end of the negotiations in what would be starting to be the run-up to a general election", she said.
"I've taken this decision because I genuinely believe it is in the national interest", May told BBC radio.
The meeting comes fresh of the heels of comments from U.S. President Donald Trump, after he told the Wall Street Journal that the dollar was "getting too strong".
May had repeatedly ruled out a snap election but clearly wants to capitalise on the Conservative party's lead in the polls, now running at more than 20 per cent. Elections are now set for 2020, just a year after the scheduled completion of Brexit talks.
A survey conducted after May's announcement put her Conservative Party 21 points ahead of the main opposition Labour Party.
If approved by parliament, the election will be Britain's third general election in seven years, and it comes less than a year after the referendum that decided the United Kingdom would withdraw from the EU.
May formally notified the European Union on March 29 of Britain's intention to leave, beginning a two-year negotiating period to settle divorce terms and agree a new trading relationship. The election will be a vote on her performance so far. The main opposition Labour Party welcomed May's election call, meaning that it is nearly a foregone conclusion that May will obtain the two thirds support she needs in the House of Commons for the election to be held. "There can be no turning back", she said.
But Scotland's first minister, Nicola Sturgeon, described the decision as a "huge political miscalculation" that could help her efforts to hold a new independence referendum.
Germany's foreign minister has said he hopes that the election will lead to more clarity and predictability in the Brexit negotiations.