Parliament's rejection last night of possible British military action in Syria followed hours of debate on the use of chemical weapons.

MPs defeated a government motion and led Prime Minister David Cameron to rule out British involvement in potential US-led strikes.

Among the contributors to the earlier debate was Labour's Manchester Gorton MP Gerald Kaufman, who said Israel's past actions should be taken into account.

Sir Gerald, whose comments were echoed by fellow Labour member Paul Flynn, said: "Israel used white phosphorous in its attack in Gaza in Operation Cast Lead - I saw the consequences for myself when I went there - but Israel gets away with it because it is on the right side of what is regarded as civilised opinion. There is selectivity right the way through."

Many MPs considered the possibility of Israel being drawn into the Syrian conflict if military strikes were taken against President Assad's regime.

Labour's Preston MP Mark Hendrick said: "The Israelis will be looking, at some point short of Iran’s having developed nuclear weapons, to possibly take matters into their own hands.

"Indeed, if the situation kicks off with the western intervention in Syria, and Iran responds, and if Syria responds with an attack on Israel, that could be the perfect excuse for the Israelis to try and deal, not only with the WMD question and Syria, but also the nuclear question and Iran. We need to take these things into consideration before we decide."

There was a "unique duty" for Britain to protect Israel, Ben Gummer, Conservative MP for Ipswich, told the House of Commons.

Bob Blackman, the Tory Harrow East MP, warned of the potential damage to the Israeli-Palestinian peace talks if the conflict escalated.

Hendon MP Matthew Offord intervened as Respect MP George Galloway spoke. Mr Offord asked about comments made by Mr Galloway on Press TV.

"One constituent claims that he said that Israel supplied the chemical for the attacks in Syria," said the Conservative MP. "I find it very hard to believe that [he] said that.

"Would he like to take this opportunity to refute that claim or to provide the evidence to satisfy my constituent?"

Mr Galloway had said last week, on the programme he hosts on Press TV, that his theory was that Israel could have supplied the gas used in the attack in Damascus last week that left hundreds dead.

In response to Mr Offord he told Parliament: "That just shows the unreliability of green-ink letters, whether they come in the post or by e-mail. I said no such thing."

The Bradford West MP later took to Twitter and wrote: "I see that malignant tub of lard [Adam Boulton, Sky News political editor] has joined the Hendon-Israel brigade."

A number of Twitter users claimed Mr Galloway had lied to the Commons and called for action to be taken by Parliamentary authorities.