The move follows the announcement by Home Secretary Alan Johnson that the legal high, which has been linked to up to 25 deaths in England and Scotland, will be banned and made a Class B drug. He also outlined an immediate ban on importing the drug.

It came after Mr Johnson was given a report backing a ban on mephedrone - also known as M-Cat or Plant Food - from Professor Les Iversen, chairman of the Advisory Council on the Misuse of Drugs.

Following talks at the Home Office with Prof Iversen, Mr Johnson said he had accepted the council's advice.

The ban will cover not just mephedrone but all similar substances in a group called cathinones and is likely to come into force by the end of April.

He said: "As a result of the council's swift advice, I am introducing legislation to ban not just mephedrone and other cathinones but also to enshrine in law a generic definition so that, as with synthetic cannabinoids, we can be in the forefront of dealing with this whole family of drugs.

"This will stop unscrupulous manufacturers and others peddling different but similarly harmful drugs.

"In the meantime, I have banned the importation of mephedrone, other cathinones, and all products containing these drugs with immediate effect.."

Prof Iversen said the rise of mephedrone was an "alarming trend" and the growth in use was unprecedented.

The advice from the committee said mephedrone was similar in its effects to amphetamines. It can cause temperature changes, heart palpitations and paranoia, the advisers said.