BIRMINGHAM England (Reuters) – Prime Minister David Cameron said on Tuesday he would not be heartbroken if Britain left the European Union because he felt little attachment to a relationship he said was not serving British interests.

Cameron, who has promised to renegotiate Britain’s EU membership if re-elected before offering voters an in-out referendum by 2017, is under pressure from the anti-EU UK Independence Party (UKIP) and some of his own lawmakers to toughen his rhetoric on Europe.

“I feel about a thousand times more strongly about our United Kingdom than I do about the European Union,” Cameron told BBC radio when asked about a statement he would have been heartbroken to see Scotland leave the United Kingdom.

Cameron said his preference was for Britain to stay in a reformed EU after a new settlement with Brussels, but said that the relationship was not working.

When asked whether it would break his heart to see a British EU exit, he said: “The United Kingdom was an issue of heartbreak. This is a matter of important pragmatism: What is best for our United Kingdom? How do we get the best deal for Britain? That is what I feel strongly about.”

The British Conservative party’s schism over Europe has marred Cameron’s last major party conference before the 2015 election, overshadowing his attempt to pitch a growing economy and lower welfare spending to voters.

The defection of a second Conservative lawmaker to UKIP on the eve of the conference ratcheted up the pressure on Cameron to take a tougher line on Europe, immigration and welfare less than eight months before a national election in May.

Under pressure from his own party to deepen his Eurosceptic accent, Cameron is also anxious not to offend German Chancellor Angela Merkel, Europe’s most powerful leader, who could scupper any British attempt at an EU renegotiation.

He has so far garnered only limited backing for his plans among other EU states and while Merkel does favour EU treaty change, she sees it as much more limited in scope than Cameron and as a way of deepening euro zone integration.

UKIP, led by Nigel Farage, could win its first seat in the British parliament on Oct. 9 – the day Cameron turns 48 – after lawmaker Douglas Carswell switched to UKIP.

Senior Conservatives admit Carswell could win the seat for UKIP, but Cameron has warned voters that supporting the anti-EU party could split the Conservative vote in what is expected to be a very close 2015 election, paving the way for the opposition Labour party to gain power.

“There is a renegotiation to be done that gets you guarantees on the single market, an end to ever closer union, better guarantees on immigration, a solution to many of the problems Britain finds in the EU. I believe that can be done,” Cameron said.

“If I didn’t think it was in Britain’s interest to be in the EU, I wouldn’t argue for it. I think the best answer for Britain is a reformed position in the EU because we are a trading nation: We don’t just want access to those markets we want a say over the rules.”

(Reporting by Guy Faulconbridge; Editing by Andrew Osborn)