BBC presenter Huw Edwards is backing a plan for "a little sister" to the Wales Millennium Centre in his home town.
The Works is one of three bids shortlisted from Wales
The "iconic" £25m building, The Works, would house a theatre, gallery and workshops on Llanelli's coast.
It is one of three Welsh bids and 23 in the UK to be shortlisted for a share of £140m from the Big Lottery Fund's Living Landmarks programme.
Mr Edwards, who is fronting the bid, said it would be a major boost for the arts in west Wales.
Details of the development were unveiled at the National Botanic Garden of Wales.
Carmarthenshire Council is seeking £18m in lottery cash towards the cost.
Mr Edwards told the launch: "Lots of schemes I'm asked to back have lots of merits, but from the moment I saw this I was impressed.
"I instantly felt it was not just worth backing, but worth pursuing until it becomes a reality.
"The great thing that commends this project is the fact for me it's so transparently inclusive.
"This provides a facility for all sectors and I can image it being widely used by local schools, drawing in people from the elderly community and offering a range of activities that bring people in.
"There is very obvious gap in the market - we need to get to a position where people are easily convinced that it will add to Llanelli's life and to west Wales.
"Llanelli because of the economic struggle some years ago has taken a while to come through the process of regeneration and it is well on its way now - I feel this would be the icing on the cake."
Almost 200 bids were originally put forward and each of the 23 on the shortlist have been given money to develop their plans. A decision on the successful applications is expected around October.
The Works would be sited on the town's Old Castle Works site boarding the Millennium Coastal Park.
Council leader Meryl Gravell said: "This is the next key stage in long-term regeneration plans for Carmarthenshire.
"It will fill a cultural void - a little sister for the Wales Millennium Centre.
"It already has major support - The Works will be an iconic building."