The dramatic announcement caps almost a year of tumult in British politics following the Brexit vote in June 2016 that included the resignation of May's predecessor David Cameron and her rapid rise to power last year.
"Despite predictions of immediate financial and economic danger, since the referendum we have seen consumer confidence remain high, record numbers of jobs, and economic growth that has exceeded all expectations".
"There should be unity here in Westminster, but instead there is division".
Aberdeen Asset Management's fixed income investment manager Luke Bartholomew said: "The election should hand Theresa May a much bigger mandate to stand up to the harder line, anti-EU backbenchers which now hold a disproportionate sway over her party's stance on Brexit".
The Liberal Democrats and other opposition parties have also indicated they will vote in favour of a new poll.
"If we do not hold a general election now, their political game playing will continue".
The Labour Leader Jeremy Corbyn has said that he welcomes an early election.
"Since I became Prime Minister I have said that there should be no election until 2020".
That Number 10 narrative was scrapped on 18 April when May called for a snap general election on 8 June, just over a month after the local and metro-mayor elections on 4 May. A new ballot offers her the chance to seek her own mandate and to increase the Conservative Party's narrow majority in the House of Commons, where it holds 330 of 650 seats.
"Because what they are doing jeopardises the work we must do to prepare for Brexit at home and it weakens the government's negotiating position in Europe".
"If we do not hold a general election now their political game-playing will continue, and the negotiations with the European Union will reach their most hard stage in the run-up to the next scheduled election".
The European Commission has said it wants the exit talks to be concluded by October 2018 at the latest and stressed in an initial reaction to May's shock announcement that the plans were unchanged.
The 67-year-old enjoys grassroots support from left-wingers but is opposed by most of the party's more centrist lawmakers, who say that Labour under his leadership is not appealing to the middle classes.
"If you want to avoid a disastrous hard Brexit, if you want to keep Britain in the single market, if you want a Britain that is open, tolerant and united, this is your chance", he said. "We look forward to showing how Labour will stand up for the people of Britain".
But she said Tuesday she had "reluctantly" changed her mind.
"Only the Liberal Democrats can prevent a Conservative majority".