The Conservatives are set to win the most Welsh House of Commons seats for the first time in 100 years, according to a YouGov poll published on Monday 24 April.
The survey for ITV and Cardiff University, of more than 1,000 Welsh voters between 19 and 21 April, put the Tories on 40% (+12).
Labour, who currently hold 25 of the 40 parliamentary constituencies, are on 30 (-3). Plaid Cymru (13%) are expected to hold onto their three seats, while the Welsh Liberal Democrats (8%) retain Ceredigion.
"Something extraordinary could be about to happen," said Cardiff University's Professor Roger Scully.
"Wales is on the brink of an electoral earthquake. The Conservatives appear to be on course to win the majority of Welsh parliamentary seats for the first time in the democratic era, while Labour faces losing a general election in Wales for the first time since 1918."
The research also revealed that Ukip's support in Wales has plummeted from 13% to 6%, with Theresa May set to deliver on the UK's decision to split from the EU.
"We need a general election and we need one now. Because we have at this moment a one-off chance to get this done, while the European Union agrees its negotiating position and before the detailed talks begin," the prime minister told the British electorate.
The YouGov survey for Wales is consistent with national opinion polls. The latest ICM survey for The Guardian, of more than 2,000 people between 21 and 21 April, gave the Tories a 21 point lead over Labour (48% versus 27%).
A separate poll from Survation for The Mail on Sunday, of more than 2,000 people between 21 and 22 April, estimated that the Conservatives had an 11 point lead (40% versus 29%). The general election is scheduled for 8 June, a month after the local and metro-mayor elections on 4 May.
Projected number of Welsh seats
Conservatives: 21 seats (+10).
Labour: 15 seats (-10).
Plaid Cymru: 3 seats (no change).
Liberal Democrats: 1 seat (no change).
Source: YouGov/Cardiff University.