Plaid Cymru is to set out its vision for an alternative Welsh Assembly government as its annual conference begins at Llandudno on Thursday.

Delegates' speeches will concentrate on the key themes of the economy and public services.

It comes eight months before the second ever elections to the Cardiff Bay institution.

Dragon's Eye survey

Rhodri Morgan speaks for: All Wales: 29% South Wales: 46% Don't know: 25% Ieuan Wyn Jones speaks for: All Wales: 26% North Wales: 31% Don't know: 47% Source: Market Research Wales Ltd for BBC Wales (sample size: 500 people)

The party will want to ensure it can build on the big political inroads made at 1999's inaugural election, when support for Plaid in Labour heartlands swelled.

Party president Ieuan Wyn Jones will use the conference to outline his challenge for Rhodri Morgan's job as First Minister.

But Plaid may have a tough job on its hands to sustain the gains of three years ago, with Labour now in a power-sharing coalition with the Liberal Democrats.

Plaid's 1999 gains in uncharted territories like Llanelli - traditionally, a staunchly Labour-voting seat - came after broadening the party horizons.

But it must continue to appeal to core voters in its heartland, largely Welsh-speaking communities.

These areas have been the focus of intense wrangling over policy to safeguard the future of the language, with a handful of minor defections from Plaid to fringe lobby groups like Cymuned.

Head-to-head contest

And new research BBC Wales politics programme Dragon's Eye has shown Ieuan Wyn Jones is losing the head-to-head popularity contest with arch rival Mr Morgan.

Almost twice as many of the 500 people surveyed around Wales favoured the Wales Labour leader to the Plaid Cymru president for leader of the Welsh Assembly Government.

The findings could make depressing reading for both parties, however.

Most people surveyed believed Mr Morgan and Mr Jones speak only for their indigenous south and north Wales respectively.

Dragon's Eye presenter David Williams said: "It's good to come back to a new run of Dragon's Eye with this hard evidence to shake up all of Wales' politicians.

"I hope it will make them sit up and think."

Dragon's Eye returns in a new series on Thursday, September 19.

BBC 2W, 2030 BST and BBC One Wales, 2335 BST.