Moody's warns Brexit would risk UK's credit rating

Credit ratings agency said the economic costs of Britain leaving the EU would outweigh the benefits

A vote to leave the EU in June's referendum will threaten the UK's strong credit score, potentially pushing up the cost of government borrowing, the ratings agency Moody's has warned.

On Monday the pound tumbled on growing fears of a Brexit, hitting a seven-year low against the US dollar and also weakened against other big currencies as investors pulled money out of UK assets. Currency experts said London mayor Boris Johnson coming out for the leave campaign intensified pressure on sterling.

Related: Pound hits seven-year low after Boris Johnson's Brexit decision - business live