Junior Minister Gerry Kelly has said the Executive has unanimously agreed there should be a ban on mephedrone.
The Executive discussed the legal drug on Thursday and Mr Kelly said all ministers hope the Home Office would act swiftly to outlaw the substance.
Mr Kelly said they could send out the message on behalf of the people of NI "to say very strongly that this drug needs banned".
The drug was also discussed by the assembly's heath committee on Thursday.
The responsibility for outlawing and classifying drugs rests with the British government and will remain there even when law and order powers are devolved to Northern Ireland next month.
"There is an expectation that the advisory council on the misuse of drugs will come through on this," Mr Kelly said.
"There's been some criticism obviously of delay because there's a worry that criminals will stockpile this and put it on the street when it becomes illegal."
On Thursday, the health committee was told mephedrone could be banned within weeks.
The committee chair, Jim Wells, said he was concerned that the general election could delay a ban.
Mr Wells said the longer it took the greater opportunity people had to buy the drug legally.
"If it's delayed there's quite a lot of evidence of people buying large quantities of this particular potion because they are expecting a ban," he said.
Health Department legislative expert Linda Devlin assured Mr Wells a ban could be enacted rapidly even with an election campaign.
"The process would be that a draft order in council would be laid before both houses of parliament so it would have to go through the House of Commons and House of Lords," she explained.
"But even if a general election were to be called today or tomorrow the convention is that there will be a few days, there's a always a few days that urgent business can be taken through.
Mephedrone has effects similar to amphetamines and ecstasy.
The substance, known by names such as Mcat, meow and bubbles, is available over the counter in "head shops" across the UK.
Public fears about the drug have intensified since the death of two teenage friends in England last week.
Louis Wainwright, 18, and Nicholas Smith, 19, died in Scunthorpe, Lincolnshire, after taking a cocktail of substances including mephedrone, heroin substitute methadone and alcohol.
In Northern Ireland a number of recent suicides have been reportedly linked to depression caused by misuse of mephedrone.
However the legal high has not been definitively established as a cause of death.
BBC News N Ireland
Friday, 26 March 2010