David Cameron criticised for pro-EU conference speech
David Cameron's pro-EU comments in a conference speech have sparked a fresh row with Conservative Eurosceptics.
He told the Welsh Tories in Llangollen that Wales' future depended on voters making the "right choices" in the assembly election and EU referendum.
The prime minister stressed the value of the EU to farmers in particular.
Ex-Welsh Secretary David Jones said he was "disappointed" Mr Cameron used his platform to promote the EU cause when the party was supposed to be neutral.
Addressing party members on Friday, the prime minister said: "Let us remember - this isn't some abstract question.
"These are actually people's jobs, people's livelihoods, people's life chances, people's families we're talking about.
"I say don't put them at risk - don't take this leap in the dark."
Mr Cameron added that he "loved Britain, not Brussels", but felt it was in the national interest to stay in the EU.
Clwyd West MP Mr Jones - who intends to vote to leave the EU in June - said: "The party announced last September that it would remain neutral in the referendum campaign.
"It is therefore very disappointing that the prime minister should use a Conservative conference to promote the Remain cause, particularly when no other speakers are being allowed to speak in favour of Brexit.
"It is important that everyone in this debate from the leader down should play by the rules if party unity is to be maintained."
Two other senior Welsh Conservatives expressed "concern" and "surprise" to BBC Wales that the prime minister's speech focused on the EU rather than the assembly campaign and Welsh Tory leader Andrew RT Davies.
Earlier on Friday, Mr Davies - who wants the UK to leave the EU - made no reference to the June referendum in his own address to the conference.
Instead, he made his bid to win the assembly election in May, saying Welsh Labour was a "lazy, complacent" government which had "run out of steam" after 17 years in power.
Aside from his comments on Europe, Mr Cameron called on voters to give the Conservatives a chance of power in Cardiff Bay, to deliver "real change" and create a Welsh "powerhouse".