Syria crisis: What is in Damascus letter to UK?
29 August 2013 Last updated at 13:49 BST
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.