The chairman of the French central bank, Christian Noyer, has said ratings agencies should downgrade the UK before France because its economy is weaker.
US agency Standard and Poor's recently warned Franceits rating could suffer over the eurozone crisis and downturn.
"The downgrade does not appear to me to be justified when considering economic fundamentals," Mr Noyer said.
The British Government responded by saying the UK had a credible plan for dealing with its deficit.
Speaking to French regional newspaper Le Telegramme, Mr Noyer said any downgrade should start with Britain "which has more deficits, as much debt, more inflation, less growth than us and where credit is slumping".
Britain was not identified as a credit risk by Standard and Poor's in its report earlier this month.
The spokesman for UK Prime Minister David Cameron said: "Credit ratings are a matter for credit rating agencies but we've put in place a credible deficit reduction plan and you can see that credibility in the UK's bond yields."