Lack of unity on the EU, UK government challenges and UKIP all contributed to the Welsh Conservatives losing seats at the assembly elections, leader Andrew RT Davies has said.

He has spoken for the first time why he feels they lost ground at the election.

The Tories lost three seats and Plaid Cymru became the main opposition to Labour, who fell short of a majority.

Mr Davies said his vision for a "one nation Conservative Wales" had been put "on hold for another five years".

Writing in the Sunday Times, Mr Davies argued his party will need to do more to strengthen perceptions of what makes its brand "uniquely Welsh".

"We must now roll up our sleeves," he said.

The Tories lost three assembly seats finishing with 11 and was overtaken by Plaid Cymru who gained one seat to come to a total of 12.

UKIP gained seven seats in the Welsh Assembly for the first time.

Outlining his reasons, Mr Davies said UKIP candidates were able to "deftly muddy much of the pre-election debate with talk of non-devolved issues such as immigration and the EU referendum, which undoubtedly resonated with many voters who went on to award them their second vote on the ballot paper".

Image copyright EPA Image caption Whoever replaces David Cameron should 'unite the party on all fronts', said Mr Davies

He added: "Others have pointed to the effect of the referendum on party unity.

"With so many senior figures nailing their colours to opposite sides of the mast, one can only wonder at the effect this had on our Conservative message."

Mr Davies had himself made clear in February that he would be voting for Britain to leave the EU.

"I felt I had no choice but to do the honest thing by declaring publicly my personal position on what remains the biggest constitutional question we have faced in a generation," he said.

He went on to write about devolved matters which he said were further overshadowed in the form of a "flurry of highly-publicised challenges confronting the UK government during the assembly election period".

"A turbulent climate for our colleagues in London fast became our turbulent climate," said Mr Davies.

'Armchair generals'

How much of a distraction this would be became apparent during Mr Davies' BBC Ask the Leader debate in Swansea.

"For 30 minutes I fielded questions from an audience mostly concerned with issues beyond the control of our devolved legislature," he said.

"This at a time when I should have been pitching my party's plans for a better health service and education system for Wales."

Mr Davies also said it "cannot and must not be ignored that as a party we need to do more to strengthen voter perception of what makes our brand of conservatism uniquely Welsh, and not allow ourselves to be constrained by Westminster or vulnerable to events across the border".

He added: "We must no longer be content to barrack from the side-lines like armchair generals.

"We must now roll up our sleeves, go back to the drawing board and develop progressive one nation solutions to the issues that matter most to Wales."

The leader said it was worth noting that "unlike Labour, Welsh Conservatives held on to all its constituency seats and took a greater share of the constituency vote than Plaid Cymru, despite suffering regional losses".

With Prime Minister David Cameron not wanting to carry on for a third term Mr Davies said, whatever the outcome of the referendum, 23 June "will set in motion the search for a new UK Conservative leader, who possesses the qualities to unite the party on all fronts and move us forward as a family unit, and back the progressive, distinguishable, vote-winning brand of Celtic conservatism".