A group of 30 leading British figures have thrown their weight behind a campaign to prepare Britain for adopting the euro.

In a letter to the Sunday Times newspaper, the company heads back the Prime Minister, Mr Tony Blair, in his decision to lead a campaign to argue the case for joining the currency.

"This is not a party political issue," the letter said. "It is an issue about the future of our country. More than half of Britain's trade is with the European Union and without constructive engagement with the EU we will fall behind. That is why we fully endorse the need to argue against that vocal minority who want Britain to leave the EU."

The letter was signed by Nestle UK chairman Mr Peter Blackburn, Vickers Plc chairman Sir Colin Chandler and 28 others.

Meanwhile, Sweden's Prime Minister, Mr Goran Persson, said yesterday that he expected Sweden to hold a referendum on whether to join Europe's economic and monetary union (EMU).

It was the first time Mr Persson has stated precisely how euro-sceptic Sweden would take a decision on EMU membership. He has previously said the issue would be decided either through a referendum or a general election, which is due in 2002.

However, the leader of the minority Social Democratic government would not be drawn on a timetable for a referendum and said he personally remained undecided on the question of EMU membership.

"There will be a referendum about this. That is my view," Mr Persson said in his annual summer speech held at Bjorkvik, south of Stockholm.

Sweden opted to stay outside EMU at its start in January 1999 due to strong public opposition and adopted a wait-and-see stance that has left the door open for future membership.

Latest polls show Swedes are still anti-EMU. A poll last week showed 55 per cent opposed to joining EMU, 40 per cent in favour and 5 per cent undecided.