London, Muharram 19, 1433, Dec 14, 2011, SPA -- British Prime Minister David Cameron showed himself to be unrepentant Wednesday about vetoing European Union (EU) treaty changes, amid calls for him to re-enter the negotiations, dpa reported. Cameron told parliament he would make "no apologies for standing up for Britain" at last week's summit, where he became the first British leader in history to use a veto at the EU. However, he remained under pressure over his stance from both the opposition Labour Party and the Liberals, who are in a coalition government with Cameron's Conservatives. Labour leader Ed Miliband called on Cameron to re-enter the negotiations, to get a better deal for Britain after having made a "terrible mistake." Earlier, Liberal Democrat leader Nick Clegg told a meeting of business representatives in London that it was now important for Britain to "re-engage" with its European partners. Despite differences of opinion "between the parties within the government," Clegg said the whole government was absolutely determined to make sure that Britain remained "at the heart of the single market." Cameron also acknowledged differences between him and Clegg over Europe, but added: "It's not that bad. I mean, it's not as if we're brothers or anything." The remark was understood to be an allusion to widely reported tensions between Miliband and his high-profile older brother, David, the former foreign secretary, who lost out to Ed in the 2010 contest for the Labour Party leadership. --SPA 18:53 LOCAL TIME 15:53 GMT www.spa.gov.sa/952534