Syria's Foreign Ministry hit out at UN peace envoy Lakhdar Brahimi, accusing him of "flagrant bias" after he raised doubts about President Bashar al-Assad's future.
Mr Brahimi told the BBC that Syrian people thought a single family ruling for 40 years was "a little bit too long" and "the time of reforms granted magnanimously from above is past."
The ministry said it was "astonished" that Mr Brahimi had not read and analysed the president's Sunday policy speech, "which is the only exit to the Syrian crisis."
today also saw the first major prisoner swap of the conflict since its start almost 22 months ago.
Rebels released 48 Iranians that they accuse of being members of Tehran's Revolutionary Guard.
Iran said the men - held since August - were pilgrims visiting Shia sites in Syria.
In return Syria released 2,130 prisoners, reportedly including four Turks and a number of Palestinians.
As Aslef's annual assembly of delegates begins in Edinburgh tomorrow the general secretary explains the challenges his members - and workers across the country - face