|Peter Hain, the former Wales and Northern Ireland Secretary, has confirmed he has resigned from the shadow cabinet.|
The 62-year-old Neath MP and current shadow Welsh secretary has resigned his position in order to campaign for the building of a Severn barrage.
There had been speculation earlier this month that he would step down after chairing Labour's successful local election campaign in Wales.
Among the frontrunners to replace Mr Hain is Pontypridd MP and shadow treasury minister Owen Smith.
Other names likely to be linked to the post are Cardiff West MP Kevin Brennan, Chris Bryant (Rhondda), Huw Irranca-Davies (Ogmore) and Nia Griffith (Llanelli).
Mr Hain, who was brought up in South Africa, was a cabinet minister under both Tony Blair and Gordon Brown.
Speaking to BBC Radio Wales he said: "I want to make a different contribution.
"I want to take forward the vital project, the biggest investment ever in Wales, £30bn investment, for the Severn barrage, and also the biggest single source of renewable energy in Europe and one of the biggest in the world.
"That's what I want to do and you can't really do that as shadow secretary of state.
"It's a post that in government I've done for nearly eight years and in opposition for two years and I think it's the right time to make this change."