British Prime Minister David Cameron says he will demand greater freedoms for London's sprawling financial industry as his price for supporting any new European Union treaty to solve the euro crisis.
The Conservative leader faced demands from some U.K. lawmakers, however, to go much further.
Answering questions Wednesday in the House of Commons, Cameron said solving the crisis threatening the euro was in Britain's national interest _ even if it is not one of the 17 European nations that use the common currency. He said he will be seeking safeguards for London's financial sector at Friday's summit in Brussels of European heads of state.
Cameron said Britain's financial services sector is "a world-class industry not just for Britain but actually for Europe."
"But it is absolutely vital that we safeguard it. We do see it under continued regulatory attack from Brussels," he said. " I think there is an opportunity, particularly if there is a treaty at 27, to ensure some safeguards, not just for that industry, but actually to give us greater power and control in terms of regulation here."
Britain's banks are particularly concerned that some EU countries are advocating a tax on every financial transaction, the so-called "Robin Hood tax." Cameron's government has been emphatic in rejecting this concept.
"(This) is in the interest of the entire country and something I will be fighting for on Friday," he said.
The 27-nation European Union and the 17-nation eurozone have been struggling with how to tame the continent's sprawling debt crisis and keep the eurozone from breaking up.
German Chancellor Angela Merkel and French President Nicolas Sarkozy have demanded changes to European Union treaties to tighten controls over spending and borrowing for all who use the embattled euro. But Britain has threatened to put the brakes on treaty changes, fearing they would force a greater transfer of power from London to Brussels and curb British influence in the EU.
If an agreement on protecting the euro involves only the 17 countries that use the currency, Cameron suggested there was less leverage for Britain to seek concessions.
Some members of Cameron's Conservative want a more aggressive negotiating stance.
Conservative legislator John Baron urged Cameron to go for "a fundamental renegotiation of our relationship with the EU based on free trade and competitiveness, which other countries enjoy, and not political union and deadweight regulation?"
"This EU summit is a defining moment, a once-in-a-lifetime opportunity. Will you seize the moment?" Baron asked.
Cameron said even if the EU goes for a 17-nation settlement "we have some leverage" and that "we should make the most of it."
Another Conservative lawmaker, Andrew Turner, called for treaty changes on immigration, employment and fishing rights.
"Clearly, the more changes eurozone countries want to do in a treaty of 27, the more changes they want to make, the greater the ability we have to ask for sensible things that make sense for Britain," Cameron said.
Opposition Labour Party leader Ed Miliband sought to exploit Conservative tensions over Europe by reminding Cameron of recent promises that he would seek to repatriate some powers from Brussels to London. Miliband asked which ones Cameron would be seeking to regain on Friday, but Cameron avoided identifying any particular issues.
"We will have the key aim of helping to resolve the eurozone crisis," the prime minister said.
He said eurozone countries must be more closely involved, and if that means they change the treaties that govern all 27 EU nations, "we will insist on some safeguards for Britain."
"Obviously, the more that countries in the eurozone ask for, the more we will ask for in return," Cameron added. "But we will judge that on the basis of what matters most to Britain."