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Boris Johnson needs to show "maturity" after being elected new Conservative leader, Wales' First Minister Mark Drakeford has said.

Mr Johnson beat Jeremy Hunt in a poll of Tory members, winning 92,153 votes to his rival's 46,656.

Welsh Labour's leader said he hoped Mr Johnson would show "strategic thinking and honesty needed to meet the challenges he, and we all, face".

The Tory MP is set to become the next prime minister on Wednesday.

Mr Johnson supporter and Welsh Secretary Alun Cairns said the new leader "will be a prime minister who can be the bridge between our great nations to get on and deliver Brexit".

"Boris shares my number one ambition for a stronger Wales as part of a strong United Kingdom," he said.

But Plaid Cymru leader Adam Price said the Conservative Party had elected a "clown".

"This is no joke. People will soon realise, this isn't as good as it gets. By electing Boris Johnson, the question of Welsh independence is not of 'if', but 'when'," said Mr Price.

The previous Plaid leader, Leanne Wood, went further, tweeting: "We now have a racist and a bigot as prime minister."

The party's Westminster leader Liz Saville Roberts said the Conservative Party had "just thrown the UK out of the frying pan and into the fire".

Image caption Mark Drakeford said the prime minister needs to react with "seriousness" to the issues facing him

In an interview with BBC Wales Mr Drakeford refrained from directly criticising the new Conservative leader.

He said it was hard to imagine "any incoming prime minister with a more serious set of issues in front of them" - listing Brexit and the future of the United Kingdom itself.

"We will need a prime minister who will react with the seriousness that is needed in order to be able to tackle those issues," he said.

Mr Drakeford said the next PM should do so "not in a sense of vacuous optimism, or relying on rhetoric, but prepared to do the serious and hard work necessary if those issues are to be addressed."

Everything must be done to avoid a no deal Brexit, he said. Welsh ministers have warned of severe economic damage if that takes place, but Mr Johnson has not ruled it out.

Boris Johnson has promised to leave the EU on 31 October - "do or die". The sitting PM Theresa May has failed three times to get a deal passed in the Commons.

Mr Drakeford called for a further referendum if the new PM cannot find a deal that the Commons can support.

In a tweet the first minister said he hopes Mr Johnson "will be able to demonstrate the maturity, strategic thinking and honesty needed to meet the challenges he - and we all - face".

Welsh Conservative leader in the assembly Paul Davies said he voted for Mr Johnson "as I believe that our current political situation calls for charismatic, uplifting and positive leadership, which as our leader Boris will deliver".

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Analysis - Felicity Evans, BBC Wales political editor

Many Welsh Conservatives feel Boris Johnson is the leader who can pull them out of the doldrums.

Despite the loyalty of most Welsh Conservative MPs, Theresa May was unable to break the Brexit deadlock in her own party, never mind in the House of Commons.

Senior figures think if (and it's a big if) he can deliver Brexit - as he has promised - the Conservative Party can stop its self-sabotage and unite to win the next election.

But others worry about a possible no-deal Brexit and its implications for the Welsh economy.

The new leader's first big test will be next week in the Brecon and Radnorshire by-election.

The honeymoon could be short lived.

Skip Twitter post by @AndrewRTDavies Congratulations @BorisJohnson – a man who believes in our great nation and is intent on delivering Brexit, defeating Jeremy Corbyn and improving prosperity for all four corners of the UK. He’s a proven winner and the right man to take the @Conservatives forward. — Andrew RT Davies (@AndrewRTDavies) July 23, 2019 Report

Former Brexit minister David Jones, said the result was "excellent news for the majority of Welsh voters who voted to leave in 2016".

"People in Wales want to see Brexit delivered and move on with their lives. Boris will achieve precisely that," he said.󠁧󠁢󠁷󠁬󠁳󠁿

Christina Rees, Labour's shadow secretary of state for Wales, called for a general election.

"Boris Johnson has won over the Conservative Party but he is yet to win over the country. He should seek a mandate from the people," she said.

Mark Reckless, Brexit Party assembly leader, said it had been clear for a number of weeks who would win the contest.

"What is less clear is whether the new prime minister will take us out of the EU in October, as he has promised," he said.