In talks with the Wales secretary, a Plaid Cymru delegation has set out the conditions under which the party will campaign for a "yes" vote in the European constitution referendum.

A delegation from the nationalists, including parliamentary leader Elfyn Llwyd and MEP Jill Evans, urged Peter Hain to raise the profile of Wales in European Union affairs.

They delivered a five point list of conditions on which Plaid is seeking clarification from ministers.

The party has so far declined to say whether it will campaign for a "yes" vote, although as a traditionally pro-European party that is seen as the most likely decision.

The nationalists are calling for the constitution to be translated into Welsh and for the Cardiff assembly to be consulted by the UK government before the Commission publishes proposals relevant to its powers.

Plaid is also seeking a role for the devolved administration in deciding how to exercise "subsidiarity" powers and Welsh representation on "all relevant UK delegations" to EU ministerial meetings.

And the result of the referendum on the constitution should also be declared separately for Wales, Scotland, England and Northern Ireland, they say.

Following the talks, Llwyd said a degree of consensus had been reached.

"The meeting was very positive and we are heartened by Mr Hain's response to the matters we raised regarding Wales' voice in the European Union," he said.

"Mr Hain rightly accepts the argument that if we are to engage the people of Wales in an informed and inclusive debate on the European constitution, then it is a prerequisite that the document is produced in the language of choice.

"Mr Hain was also concerned to hear examples we sited where there has been insufficient consultation with the National Assembly and the Labour Assembly Government on matters directly relating to Wales."

Plaid added that Hain agreed with "full consultation and representation" and had also accepted the call for referendum results to be announced for each of the four nations.

Evans added that "there remain several issues that need substantial further discussion".

"Peter Hain's comments on translating the European constitution into Welsh were encouraging, but we are still looking for a commitment from the government that this will happen," she said.

"We were also able to make an initial case for Welsh to become one of the EU's official languages.

"We need to see this in the context of the new developments in Spain where the government is making a strong case for Catalan and Basque to become official languages. If it's good enough for them, then why not Welsh?

"As regards the council of ministers, we have a long way to go to make sure that assembly ministers are regularly part of UK delegations, but we will continue pushing for this."

In his own comments following the talks, Hain indicated he was "sympathetic" to calls to translate the constitution into Welsh.

But he added that responsibility for the issue rests with the foreign secretary, Jack Straw.