A vote for Plaid Cymru is now a vote for an independence referendum in Wales, the party has said.
Leader Adam Price has pledged that Plaid would offer a referendum if it formed a government and got a Senedd majority to back it.
It is a first for the party, which has never previously promised to offer an independence vote in the first term of a Plaid government.
But the power to call a vote would still lie with the UK government.
It allowed one to take place in Scotland in 2014 after the SNP won a majority in the Scottish Parliament elections three years earlier.
In a speech in Cardiff Bay, Mr Price said something “new and better” must come out of the Covid crisis.
“Independence is the most radical idea in Welsh politics today,” he said.
Mr Price told an audience watching via social media that devolution was “under attack” from Boris Johnson’s UK government and that Scottish demands for a second independence referendum were “unstoppable”.
“Wales is in real danger of being left behind as part of a rump United Kingdom, in a new England-and-Wales formation – which would be the ultimate worst of all worlds,” he said.
“It is for these reasons that I pledge today that, subject to party approval, a Plaid Cymru government, able to command a majority in the Senedd, will offer a referendum on independence for Wales in its first term.”
Previously Mr Price had said a referendum would take place in the second term of a Plaid government and before 2030.
The change in policy comes in response to a report commissioned by the party which recommended two referendums on independence.
The first was proposed as “multi-choice” exercise to gauge opinion, and the second a vote on the preferred option in the referendum.
Now Mr Price is promising one single vote offering a choice between independence and the status quo.
The political impasse over Brexit in 2019 saw a variety of pro-independence marches around Wales, organised by non-party political groups and attended by thousands of demonstrators.
Referencing those events, Mr Price made a direct pitch to those who attended for their support.
“Banners and marches fuel our fire, but the Welsh spring will only truly bloom at the ballot box in May. If you want independence, you have to vote for it,” he said.
After the speech the Plaid Cymru leader added: “I’m the only pro-independence candidate for first minister.
“If we’re able to form a government and get that referendum I think we’ll win it.”
This is a big move from Adam Price. Even before he became leader he said Plaid should make independence their “express purpose… sooner, rather than later” and it’s clear he feels the time is right.
Brexit, and more recently the coronavirus pandemic, have moved independence into the mainstream of Welsh political conversation, as the growth of unaffiliated, pro-independence groups attest.
Mr Price wants to harness that momentum going into next year’s elections, but it’s by no means a clear route to electoral success.
Opinion polling does suggest a rise in support for Welsh independence, but it’s a very long way from showing a consistent majority in favour.