(Sept 11): Some of Britain’s best-known companies, including Royal Bank of Scotland Group Plc, BP Plc and Kingfisher Plc, made their strongest intervention yet in the battle against Scottish independence, as RBS joined Lloyds Banking Group Plc in saying it would move parts of its business to England in the event of a breakaway.

Ian Cheshire, chief executive officer of retailer Kingfisher, which employs 3,000 people in Scotland, urged voters not to make a mistake in a “once-in-a-lifetime decision,” arguing that independence would mean higher prices and lower investment. He predicted that other chief executives will make similar statements ahead of the vote on Sept. 18.

“The referendum is the most pressing political risk that businesses face,” said John Cridland, director general of the Confederation of British Industry, the country’s leading business group. “Scottish independence would be a one-way ticket to uncertainty, with no return.”

The comments reflect an increasing willingness by British business leaders to abandon neutrality in the referendum debate.

BP Chief Executive Officer Bob Dudley said his company considers “the future prospects for the North Sea are best served by maintaining the existing capacity and integrity of the United Kingdom.” Dudley had only said previously that he thought Great Britain should stay together, but had not made the claim that North Sea oil production would be affected by a vote for independence.

Oil Doubts

Dudley was joined by Royal Dutch Shell Plc CEO Ben van Beurden in backing an assessment of North Sea oil reserves by Ian Wood, former chairman of oil engineer John Wood Group Plc. Wood questioned optimistic reserves forecasts from a think-tank linked to the pro-independence movement.

Standard Life, the Edinburgh-based financial services company that is one of the city’s biggest employers, has contingency plans to move its pensions, investments and other long-term savings south of the border if the Scots vote for independence. That prospect looked more likely as opinion polls gave the pro-independence camp a lead for the first time this week, or showed the two sides neck and neck. However, a poll published yesterday gave a six percentage-point lead to the anti-independence vote.

David Nish, Standard Life’s CEO, said the company “has a long history in Scotland -- a heritage of which we are very proud -- and we hope this continues. But our responsibility is to protect the interests of our customers, our shareholders, our people and other stakeholders in our business.”

Border Crossing

RBS said today it would move its domicile to England if the independence movement succeeds, though it would retain significant operations and jobs in Scotland. Lloyds said yesterday it has a contingency plans to establish new legal entities in England.

Alexander Leitch, chairman of health-care provider Bupa and former chairman of insurer Scottish Widows Plc, added his signature to a new 100-word statement expected from 130 company leaders arguing for preservation of the U.K., according to Sky News, which didn’t reveal its sources.

A previous letter in August carried 120 signatures, from HSBC Holdings Plc Chairman Douglas Flint to Jimmy Buchan, skipper and owner of the Amity Fish Co.

Some corporate leaders are still steering clear of the debate. Tesco Plc, Britain’s largest grocer, is “politically neutral,” the company said yesterday in a statement. “This is a decision for the people of Scotland and we will respond to whatever that decision is.”