The French evidence suggests Bashar al Assad's regime was responsible - Image: http://news.sky.com
Syrian President Bashar al Assad was behind a "massive and coordinated" chemical attack, the French government has claimed.
A seven-page intelligence report sets out five points which, MPs will be told, suggest Mr Assad was responsible for the deaths of hundreds of people in Damascus last month.
The evidence includes satellite imagery, allegedly showing the attacks were launched from government-controlled areas, a French government source told the Reuters news agency.
Mr Assad told French newspaper Le Figaro the allegations were "illogical" and warned of "negative" repercussions for French interests if the country engaged in military action.
However, the government source said: "Unlike previous attacks that used small amounts of chemicals and were aimed at terrorising people, this attack was tactical and aimed at regaining territory."
Earlier, French Prime Minister Jean-Marc Ayrault said MPs would be given every piece of evidence the government has, including information that has been classified until now.
Lawmakers are expected to debate the evidence on Wednesday.
French President Francois Hollande can order military action without parliamentary approval, although some lawmakers have urged him to put the issue to a vote, following the lead of US President Barack Obama, who decided to seek authorisation from Congress before agreeing to missile strikes.
France is the United States' main ally in the Syrian crisis, after Britain voted against military action.
Meanwhile, Russian foreign minister Sergei Lavrov dismissed evidence of alleged chemical weapons use by the Assad regime as "absolutely unconvincing".
He said the intelligence contained "nothing specific ... no geographic coordinates, no names, no proof that the tests were carried out by the professionals".
A planned peace conference to end the conflict in Syria could be put off "forever" if the US goes ahead with military action against the regime, he added.