Syria crisis: What is in Damascus letter to UK?

The Speaker of the Syrian Parliament has written to Commons Speaker John Bercow inviting a parliamentary delegation to the Syrian capital to check the UN's conclusions.

The letter added that Syria will sue those responsible in British courts if the UK attacks - which it said would be an "aggressive and unprovoked act of war".

A parliamentary vote on the UK's response to a chemical attack near Damascus currently hangs in the balance, after the opposition demanded "compelling evidence" of Syria's guilt.

The BBC's Rajesh Mirchandani takes a closer look at the letter with BBC Arabic correspondent Nahed Abuzeid.