The meeting was publicised, in contrast to several European politicians who met Meshaal in the last few months away from the spotlight.
The delegation included a second Labour member of the House of Commons and two Liberal Democrat members of the upper chamber, the House of Lords.
One Irish parliamentarian and one member of the Scottish parliament were also present.
Parliamentarians from Italy and Greece are expected to visit Damascus to meet Meshaal next week.
Calls have increased in the West to deal with Hamas after the Israeli invasion of Gaza which was halted in January.
Meshaal had urged the West lift its boycott of Hamas, which controls the Gaza Strip.
'Open to talks'
Hamas won a parliamentary election in 2006 and drove its Fatah rivals from Gaza by force in 2007.
The two groups are currently holding talks on a Palestinian unity government under Egyptian auspices in Cairo.
Britain said this month it was open to hold talks with the political wing of Hezbollah after the group joined a unity government last year.
France, which played a role in halting the Gaza war, has indicated that it might be prepared to hold talks with Hamas even if Hamas did not recognise Israel.
Leaders of Hamas have said they are not prepared to recognise Israel but would accept establishment of a Palestinian state on land occupied by Israel in the 1967 Middle East war in return for a truce with Tel Aviv lasting decades.