LONDON (REUTERS) - The British government said on Monday (Sept 9) it had received legal advice on its rights and obligations when it leaves the European Union but publishing the details would damage its negotiating position.

The Treasury made the comments in response to a Reuters query, submitted under the Freedom of Information law, about how much of Britain's 39 billion pound (S$66.50 billion) divorce bill would be due in the event of a no-deal exit.

Prime Minister Boris Johnson, who has vowed to take Britain out of the EU with or without a deal at the end of October, has said that in the event of a no-deal exit, Britain will no longer legally owe the 39 billion pounds.

The EU has said it expects Britain to honour all the financial obligations made during its membership of the bloc even after a no-deal Brexit.

Asked by Reuters whether the government had received legal advice on how much of the 39 billion pound bill would be due if Britain leaves without a deal and, if so, what amount did it advise would still be due, the Treasury said it held information "within the scope" of the request.

"HM Treasury has received legal advice on the UK's rights and obligations on leaving the EU," it said in a letter, adding that the advice was exempt from publication on several grounds.

These included that the disclosure could prejudice international relations and Britain's interests abroad.

"Release of this information at such a sensitive time would be detrimental to the government's negotiating position," it said.

The Treasury also said there was a public interest in ensuring public authorities are able to consult their lawyers in confidence and for the government to be able to develop policy "freely and frankly".

"There could be a chilling effect on the ability of the government to efficiently form policy if decision makers and their advisers knew that the discussions and advice would be revealed, particularly whilst the wider exit process is ongoing," the letter said.