Moody's Investor Services said U.K.'s top AAA rating is not immune and largely depends on the future developments in the euro area.

The rating agency referred that the outlook has deteriorated over the past year due to the anemic growth, where retaining this top rate will depend on the government's ability to stay on track with its fiscal consolidation program.

With any additional macroeconomic shocks, the outlook on the rating is likely to be sensitive to future developments in the euro area's debt crisis, Moody's said.