The UK's Association of Consulting Actuaries (ACA) has reopened the debate linking Britain's membership of the single currency to the pension liabilities of France, Italy and Germany.

The ACA's argument is not that Britain will have to pay for the liabilities directly but that higher interest rates in continental Europe will extract an indirect cost.

Speaking at the launch of the ACA's annual review in London last month, ACA chairman Paul Thornton said: Inevitably, this will have serious economic and monetary implications. Whether or not the UK has by then agreed to join a single currency, there is likely to be a significant impact on economic activity across Europe, with upward pressure on interest rate due to high levels of public debt."

He added that Britain's funded system would allow it to hold down future taxation levels but that there was already evidence of pressure from Europe to remove this economic advantage by harmonising taxes and budgets.

Talking to IPE, Thornton said that his speech which called on the Treasury to set up a study group of government, financial and pensions specialists, was an offer to get involved and to help develop thinking.

While the debate had moved on from suggestions that countries such as the UK and the Netherlands would have to pay for pensions liabilities, excluded by the Maastricht treaty, there was a "second order impact" to consider and he did not believe that research had been done on that specific subject.

He continued: "The government's stance on Europe is to try to march in step until the next election and then probably enter the currency. It would be dangerous to assume that we were marching in step if we weren't looking at the impact of these unfunded liabilities."

Thornton also flagged the fact that the International Accounting Standard on employee benefits to be approved in January, looked like it would incorporate a calculation of liability based on corporate bond yields. Actuaries have been lobbying for two years to get this changed saying that it will give misleading results, making company profit and loss accounts highly volatile."