Theresa May would be on course for a 100-seat majority if she called a snap general election this year, according to an influential pollster.
Elections analyst Robert Hayward told Sky News the Tories would surge to victory if Mrs May went to the country in the coming months, fresh from triggering Article 50.
The party could lose up to 15 seats to the Liberal Democrats, his projections suggest, but make major gains from Labour and could take a handful of seats from the Scottish Nationalists.
Lord Hayward said: "My expectation is if there was an election this year - and I don't expect there will be one - the Tory majority would be towards 100."
Mrs May has repeatedly played down the chances of a snap poll and last month her spokesman told journalists: "It isn't going to happen."
But reports suggest potential dates have been discussed by cabinet ministers, and this weekend the Labour Party was reported to have been building a funding war chest to fight one.
Lord Hayward, a former Conservative MP in Bristol, also predicted a catastrophic night for Labour in May's local elections, with losses of around 125 seats to all parties.
It is highly unusual for the main opposition party not to make gains in local elections. He predicted Labour could be on course for its worst election results since 1985 after the damaging SDP split.
The greatest losses are expected to come in Scotland with an "iconic" loss forecast in Glasgow.
Lord Hayward said the result for Labour would be a reflection of the fact the party is failing to appeal to the "old core of working class voters in the Midlands, north and Scotland".
The Conservatives are expected to capitalise on the "Ruth Davidson effect" in Scotland and gain 100 seats across England, Scotland and Wales..
The big winners are forecast to be the Liberal Democrats who are expected to make a gain of 100 seats, after a dismal drubbing at the last general election, and have a good prospect of taking control in Somerset and Cornwall.
After delivering its political "earthquake" in 2013, UKIP is expected to lose 80-90 seats, which will be a significant blow.
If the Conservatives don't call a general election by next year - which Labour MPs would have to vote for, under the Fixed Term Parliaments Act - they may have to fight seats on new boundaries.