British Prime Minister Gordon Brown has sent a letter to all overseas territories urging them to meet international banking guidelines by September or face sanctions, according to a news report in the Cayman Islands.

However, the Bermuda Government remained silent on its response last night prompting criticism from Leader of the Opposition Kim Swan.

According to the website Cayman Net News, Prime Minister Brown instructed the Cayman Islands to meet international banking standards of the Organisation for Economic Cooperation and Development (OECD).

"Underscoring his support of the G-20 push to improve international standards on tax transparency, Mr Brown sent a series of individualised letters to British Overseas Territories last Thursday 9 April, including one specifically addressed to Cayman Leader of Government Business, Hon Kurt Tibbetts," it reported.

The letter follows Cayman's inclusion in a "grey list" of nations identified by the OECD as lacking in terms of compliance with international standards.

The list was compiled during deliberations at summit on April 2 in London involving 19 of the world's 25 most-developed nations and the European Union.

Bermuda is also on the grey list, although this newspaper reported on Monday that it has moved a step nearer to being taken off after reaching agreement with the Netherlands on a tax information exchange agreement (TIEA) to be signed later this year.

The Island needs a minimum of 12 TIEAs to be considered for the "white list" of countries, considered by the Organisation for Economic Cooperation and Development to have implemented international tax information sharing standards, a tally the Government expects to achieve by the middle of next month.

Bermuda currently has three TIEAs with the US, the UK and Australia and is set to sign eight more next week, seven with the Nordic Group countries and another with New Zealand.

Germany has agreed to sign a TIEA with Bermuda in mid-May, and the Netherlands agreement should be signed in the summer, meaning that the Island should have at least 13 TIEAs in place by the next Group of 20 summit in 2010, to meet the OECD standard for the top tier of countries.

It was unclear last night whether Bermuda's leader Dr. Ewart Brown was also sent the letter by the British Prime Minister since Government press officers did not respond to inquiries from this newspaper.

United Bermuda Party Leader Kim Swan said:"Although other overseas territories have released the letter, there has been no official word from the Bermuda Government on the matter, and so we urge it to state whether such a letter has been received and, if so, to release it to the public.

"All of us in Bermuda are on the same page when it comes to getting our name off the OECD's grey list of jurisdictions that have not yet substantially implemented financial regulatory requirements. But the Government needs to be upfront and transparent about what is going on. Right now, it serves no one's interest to find out about such developments through the international media."