"While the election result will have no impact on the UK's rating, if the Conservative Party's plan to hold a referendum on European Union membership results in the UK's exit this could have consequences for the whole economy, including potentially for the sovereign rating, if the UK was unable to broadly replicate the benefits of membership," Moody's said.

Cameron has promised to hold a referendum on Britain's membership of the EU before the end of 2017.

(Writing by William Schomberg; editing by Mike Peacock)