The Independent Alliance has secured a free vote on proposed legislation allowing the use of cannabis for medicinal purposes.

The group, which consists of Minister for Transport Shane Ross and Minister of State Finian McGrath, requested a vote of conscience on the Bill put forward by People before Profit TD Gino Kenny.

The Bill aims to legislate the use of cannabis for medicinal purposes for a specific small group of sufferers.

The Alliance is seeking to support the legislation while Fine Gael will oppose it.

Fianna Fail's health spokesman Billy Kelleher said his party would be supporting the Bill.

The Bill will also be supported by Sinn Féin, the Social Democrats and the Green Party meaning it will have the support of at least 76 TDs. Labour will consider its position at a meeting of the parliamentary party on Tuesday evening.

The Bill will require the support of Mr Ross, Mr McGrath and other member of the Alliance to pass.

Fine Gael is likely to put forward a reasoned amendment, which would propose the Bill cannot be read a second time.

Minister for Health Simon Harris will say he cannot support the legislation until a review he has ordered is complete.

The Bill, which was first published last July, provides for the regulation of cannabis for medicinal use so that patients can receive a legally protected, secure supply that is safe and effective.

It is due to be debated in the Dail on Thursday.