Britain's gold-plated triple AAA status came under pressure today after a credit ratings agency put it on negative watch.

Standard & Poor's said there was a 1 in 3 chance it could lower Britain's rating within the next two years, if economic conditions weaken in the UK.

It said it expected government debt as a percentage of gross domestic product (GDP) to continue to rise in 2015, before declining again.

It said that future employment or growth shocks would put further pressure on UK government finances.

"In our opinion, many of the factors that have restrained growth in recent years will likely continue to do so in the near term,'' S&P said.