The body that advises the government on illegal drugs is to recommend ecstasy be downgraded to a Class B drug.
Ecstasy is currently grouped with heroin, cocaine, crack and LSD in Class A. Suppliers of such drugs can face a life sentence in prison.
The Home Office has made it clear it will reject the Advisory Council on the Misuse of Drugs' recommendation.
Earlier, a row broke out after the council's head Prof David Nutt likened the dangers of ecstasy to horse riding.
Home Secretary Jacqui Smith responded by accusing him of trivialising the dangers of the drug. He later apologised for any offence and said the views were not those of his colleagues on the council.
The advisory council reviewed the latest evidence on ecstasy last year and held a secret ballot of its 31 members on the issue of re-classification.
It is understood the result was not unanimous, but a majority voted to recommend moving the drug to Class B.
The council's view is that ecstasy is not as harmful as other Class A drugs and causes far fewer deaths.
It says ecstasy use had no significant impact on short-term memory loss and found little evidence to link ecstasy to criminal behaviour.
But it will call for further research into the effects of taking ecstasy, particularly on younger users.
I would like to apologise to those who have lost friends and family due to ecstasy use
Prof David Nutt
Last month, the Home Office restored cannabis from Class C to Class B, against the wishes of the advisory council.
Ministers are now set to resist the council's recommendation on ecstasy.
BBC home affairs correspondent Danny Shaw said this latest move raises real doubts about how long the council can continue in its present form if its experts continue to be ignored.
Shadow home secretary Chris Grayling said it called into question the government's choice of advisers.
But Liberal Democrat home affairs spokesman Chris Huhne accused the Home Secretary of a "ludicrous overreaction".
He added that her "savaging" of Prof Nutt was "a poor precedent for academic freedom".
The row over the dangers of ecstasy erupted followed the publication of an article by Prof Nutt in the Journal of Psychopharmacology last week.
In it, he wrote: "Drug harm can be equal to harms in other parts of life. There is not much difference between horse-riding and ecstasy."
He said horse-riding accounted for more than 100 deaths a year, and went on: "This attitude raises the critical question of why society tolerates - indeed encourages - certain forms of potentially harmful behaviour but not others such as drug use."
Ecstasy use is linked to around 30 deaths a year, up from 10 a year in the early 1990s.
Jacqui Smith said she was "surprised" and "disappointed" by his comments and told him he had gone beyond his role as head of the advisory council.
But later in a statement, the professor said: "I am sorry to those who may have been offended by my article.
"I would like to apologise to those who have lost friends and family due to ecstasy use.
"I would like to assure those who have read my article that I had no intention of trivialising the dangers of ecstasy."
Fatalities from ecstasy are caused by massive organ failure from overheating or the effects of drinking too much water.
Source - http://news.bbc.co.uk/1/hi/uk/7882708.stm