what is the procedure to get my divorce certificate authorised and stamped at the British Embassy

http://www.thaivisa.com/forum/topic/855787-changes-to-the-legalisation-procedures-for-uk-citizens-moving-to-thailand/

From the sounds of this article you cannot now. Another service reduction from Brit Embassy.

If you are wishing to get remarried in Thailand you don't get your divorce papers stamped, you get an affirmation of freedom to marry from your embassy, though you may need to prove to your embassy that you are actually free to marry.

As you are making an affirmation, basically swearing that the information you have given is correct, you will need to make an appointment to visit your embassy in person.

The details are here https://www.gov.uk/guidance/notarial-and-documentary-services-guide-for-thailand

You will need to get the affirmation translated into Thai and certified at the MFA.

The previous post refers to something else altogether.

If you are wishing to get remarried in Thailand you don't get your divorce papers stamped, you get an affirmation of freedom to marry from your embassy, though you may need to prove to your embassy that you are actually free to marry.

As you are making an affirmation, basically swearing that the information you have given is correct, you will need to make an appointment to visit your embassy in person.

The details are here https://www.gov.uk/guidance/notarial-and-documentary-services-guide-for-thailand

You will need to get the affirmation translated into Thai and certified at the MFA.

The previous post refers to something else altogether.

Hope you are right mate, it just seems to me that the Embassy services are being reduced all the time. Sorry if I misunderstood the post I referred to.