Welsh Labour’s Alun Davies said:
“Plaid Cymru have just fought an election campaign spending eight weeks saying they’d never do a deal with UKIP, or the Tories. They referred to UKIP as the “far right”. And yet today we’ve seen them stitching up a deal to try and form a government.
"The people of Blaenau Gwent, the Valleys and Wales will know they can never trust a word Plaid Cymru says in the future.
“Welsh Labour won a clear mandate in the election last week. 29 seats is a clear lead over Plaid Cymru’s 12 seats, actually a bigger lead than Labour had over the Tories in 2011. People expected us to be given the right to form a Government, and for the other parties to hold us to account on the way we perform in office.
"What we’ve seen today in an unseemly deal between two parties hurting from election defeat, and UKIP going along for the ride.
“I can only imagine what the people in our steel communities are thinking today – they want answers and they want to see us working together to save their jobs. What they’ve got is an unseemly spectacle and delay on the formation of a Government which would put all its energy in finding a sustainable future for the industry.
“We’ve also a European referendum just 6 weeks away. Carwyn had asked all progressive parties to join together in fighting to remain in the EU. Instead of that, Plaid have handed UKIP another day in the sun."