Ahead of Thursday's General Election vote, Plaid Cymru's former Carmarthen East and Dinefwr MP Adam Price writes exclusively for the Guardian to lay out his views on what's ahead.

Every election every politician says this election is the most important one in a generation. But this time they may be right. In this messy, electrifyingly unpredictable election we may yet be witnessing not just the death rattle and birth pangs of this or that party of government, we are seeing the beginning of a new politics altogether. Nations like Wales and Scotland and parties like Plaid and the SNP, once ignored, are now centre-stage.

That no one party and no one nation should have a monopoly on power has always been Plaid's message, and who can disagree. Thatcher's majority shut the pits and Blair's and Brown's destroyed Iraq, privatised health and let greed rip in the City.

For five years now, we have had a Conservative coalition. But we have the chance and the choice of a different kind of alliance, an arc of anti-austerity, a rainbow red and green.

This is a reason to be hopeful. It's when progressives work together that we've made progress: Lloyd George and Keir Hardie in 1906 giving us the pension. Labour in 1945 kept honest by the Independent Labour Party that Betws' Jim Griffiths first joined. It was Plaid Cymru during the 1970s minority Labour Government that won industrial compensation for silicosis sufferers, the establishment of the Welsh Development Agency and a promise to set up a Welsh Assembly and a Welsh Fourth Channel - eventually delivered through Plaid pressure.

That was with three MPs - imagine what we can achieve for everyone in Wales with double that at this election, or more. Fair funding for a start so we can invest in our schools and hospitals as well as the economic levers we need to bring more jobs to places like the Amman Valley.

This is a powerfully optimistic moment, an opportunity we must seize with both hands.

For the first time in forty years, Labour’s leadership, in its search for power, will be forced to look Left, not the centre, to Wales and Scotland - not Middle England or the City of London.

The reward could be every bit as great as the victories of the past: a Great Reset for politics and policy, the redistribution of wealth and power and the abolition of poverty and privilege.

It would be an irony, richly enjoyed by Gwynfor Evans and Jim Griffiths that it was Wales' voice in Westminster, Jonathan Edwards and Plaid Cymru, that helped Labour find its soul again.