Plaid Cymru Parliamentary leader Elfyn Llwyd has called on his party to drop its policy of boycotting the House of Lords.
Elfyn Llwyd said Wales needed more representation in the Lords
Plaid Cymru currently refuses to nominate peers because it wants a fully elected House of Lords.
But Meirionnydd Nant Conwy MP Mr Llwyd said the party was failing to make its voice heard in debates affecting Wales.
He said Plaid's two other MPs supported him, but that policy change could only come at the annual conference.
The only party member to sit as a peer, Dafydd Elis-Thomas, was made a Lord in 1992 following a personal decision which proved controversial.
But Mr Llwyd told BBC Radio Wales that the party's official policy must change if its voice is to be heard in the House of Lords.
"It's a personal u-turn. Ten years ago we debated this and I was certainly against the idea," he said.
"But I've been working in Westminster for the last 13 to 14 years and I've realised that we are not able to represent our country as well as we might without somebody in the second chamber."
Mr Llwyd said that Plaid Cymru needed to ensure that there were people who would "speak up for Wales" in parliamentary measures relating to Wales passed by the House of Lords.
Plaid has refused to nominate peers for the Lords
The policy cannot be changed until the party's annual conference in September, but Mr Llwyd said it was important to raise the issue now.
"I want a full mature sensible debate between now and then, none of this flummery about people in ermine once a year," he said.
"We would like a fully democratic, fully elected chamber, but I don't think there is a great deal of impetus for that to happen just now and I don't think we can afford to wait for it to happen."
He also said the change in policy was for the good of the party and did not represent a personal ambition for a peerage.
"That's certainly not on my horizon at all at the moment and frankly it's got nothing to do with my decision at all," he said.