LONDON (Reuters) - Britain intends that its controversial bank bonus tax will be a one-off and is confident it will help restrain payouts after talks with the industry over the last week, Treasury minister Paul Myners said yesterday.

"From the engagement I've had with the banking industry to date I'm fairly clear that it's not going to require it to be extended further. We've made it very clear it's a one-off tax," Myners said, speaking at the London offices of Thomson Reuters.

Britain last week unveiled a 50 percent tax for banks on any bonuses over £25,000 ($40,670) in an effort to rein in multi-million pound payouts across an industry bailed out by taxpayer cash, which critics say could lead to an exodus of bankers and make London uncompetitive.

However, other countries such as France are considering similar measures.

There have been concerns the tax could be extended if banks try to sidestep the levy, but Myners said: "The purpose is to reinforce the impact of remuneration on risk, and we would evaluate how that develops over the next three or four months."

Myners, a City veteran and one of Prime Minister Gordon Brown's trusted advisers, said the tax will be targeted at staff involved in "the activities of banking" and Britain's tax authorities would provide further clarity on its scope.

Investment managers, hedge funds, stockbrokers and others have said they are uncertain if they will be affected as the legislation has been drafted widely.