A group of 20 senior doctors have warned about increasingly relaxed attitudes towards cannabis from legislators.

The Cannabis Risk Alliance has claimed that these attitudes were "gaining ground", despite new research which shows cannabis is now the most common illegal drug involved in new treatment cases in the country's addiction centres.

A study from the Department of Health last year showed almost 25% of people who have used cannabis in the past year were classified as 'cannabis dependent'.

The 'Drug Use in Ireland and Northern Ireland' survey revealed a slight increase in illegal drug use overall.

It showed levels are up by 1.9% between 2010/11 and 2014/15 - with results indicating cannabis was the most commonly used illegal drug.

The Cannabis Risk Alliance group, made up 20 specialists in psychiatry, neurology, and addiction services - along with GPs and emergency department consultants - have said the Government is "sleepwalking" towards legalising the drug for medicinal purposes without considering the harms associated with the drug.

The doctors signed a letter published in The Irish Times.

Psychiatrist Dr Bobby Smyth of Trinity College Dublin spoke on behalf of the alliance.

He said: "Cannabis is increasingly perceived to be a harmless drug, whereas in reality it is the main drug causing new addiction-related and psychiatric cases presenting in Ireland today.

"We are gravely concerned that the Government is ploughing ahead without objectively considering the full effects of cannabis or even properly communicating the risks posed by the drug to society at large."

Dr Smyth added that it was his belief that global multinationals are influencing the Government's response to an issue that deserved more scrutiny.

"The Government is sleepwalking into supporting the use of so-called 'medicina'' cannabis while ignoring the extensive evidence of its harms.

"This gives the perception that the drug is harmless and gives the wrong message to young people".

"We call on the Government to initiate an urgent and unbiased examination of the evidence of escalating cannabis use and cannabis-related health harms in Ireland, as well as a comprehensive public education campaign to counter the pro-cannabis propaganda which has gone unchallenged for the past eight years."

Dr Ray Walley, a GP and former president of the Irish Medical Organisation (IMO), said he had seen a significant increase in the numbers of people presenting with cannabis-related issues.

"The number has shot up in recent years. This is destroying families, and the Government needs to properly investigate the harm this drug can cause before blindly introducing legislation that will have a huge effect on society.

"Cannabis has changed fundamentally in the past 20 years.

"Modern cannabis, known as 'weed', is vastly stronger than the hash which was used in the past.

"Cannabis has never been more dangerous than it is now."