One in five borrowers are concerned about meeting their mortgage repayments over the next 12 months, the Financial Services Authority said on Tuesday, reigniting concerns over rising default rates.

Launching a 2 million pound advertising campaign to help worried consumers, the FSA said almost a quarter of borrowers in trouble had no plans on how they would meet the extra cost.

"Economic conditions are getting tougher, putting pressure on family finances," Chris Pond, FSA director of financial capability said.

Despite wider economic turbulence, the rate of loan defaults and home repossessions in Britain has remained low by historic standards - particularly compared to the early 1990s - but it has risen in recent months, climbing 21 percent in 2007 to its highest level since 1999, according to official data.

But there are concerns that could change if the global macroeconomic situation and unemployment rates worsen.

The Financial Services Authority has warned that 1.4 million short-term fixed rate mortgages would end in 2008, leaving borrowers exposed to a painful jump in rates as banks pull away from loans for more than 90 percent of the property value.

Britain's high street lenders have all but scrapped deals offering borrowers more than the cost of their homes, with Northern Rock, the troubled mortgage bank, scrapping its pioneering 125 percent mortgage last month.

The FSA's mortgage tables, checklists and tips for borrowers are available on www.moneymadeclear.fsa.gov.uk.