The chairman of Lloyds Banking Group has said that there was no "compelling economic argument" for Britain to stay in the European Union without a significant change in its relationship with the bloc.

The comments by Norman Blackwell, who was addressing parliament's House of Lords in a personal capacity rather than as Lloyds chairman, are a boost to those campaigning for Britain to quit the EU in a referendum due by the end of 2017.

Conservative Prime Minister David Cameron is trying to renegotiate the terms of Britain's membership and has promised that once he has obtained a new settlement he will put the question of whether to stay in or leave to British voters.

Both the "in" and "out" camps have been seeking support from senior business figures in an effort to bolster the economic credibility of their stances. A campaign to keep Britain in the bloc launched on Monday, led by Stuart Rose, a former boss of quintessentially British retailer Marks & Spencer.

"I do not agree that remaining in the European Union without a significant change in the current treaty arrangements is ultimately sustainable from a political and constitutional perspective," Blackwell told the House on Tuesday.

"Nor do I believe that there is a compelling economic argument to override those considerations," he said during a debate on the government's referendum bill, in comments published on Hansard, parliament's official record.

Opinion polls suggest voters are split, and that crises in the EU over Greek debt and a surge of migrants may be turning some Britons against staying in the 28-nation bloc.

Blackwell dismissed concerns, often put forward by those opposed to a referendum, that the uncertainty over whether Britain would stay in the EU or not would inflict severe economic damage.

"While uncertainty may mean that some business investment is held back in the short term, there are many reasons why the UK is likely to remain an attractive global location whatever the outcome, and ignoring the democratic process may be even more costly," he said.

Blackwell, who was a senior adviser to then Conservative Prime Minister John Major from 1995 to 1997, argued that Cameron's renegotiation process should not be about winning or losing a few concessions from fellow member states.

"Rather it should be about whether we can get agreement across Europe to a new settlement that suits everyone: a new kind of treaty relationship between the UK and the eurozone members that makes it sustainable for us to become and remain a member of a wider but looser European Union club, alongside but apart from the eurozone core."