The party drug mephedrone will become illegal from Friday, the Home Office has confirmed.
The so-called legal high will be classified as a Class B drug with effect from April 16, following the completion of the formal parliamentary process.
From that date anyone found in possession of mephedrone could face five years in prison. The maximum sentence for dealing in the drug will be 14 years.
The move to ban mephedrone, which is sold over the internet as plant food, comes despite the resignation of two Government drugs advisers over the issue. Earlier this month, Eric Carlin followed Dr Polly Taylor in stepping down from the Advisory Council on the Misuse of Drugs.
In a letter of resignation, Mr Carlin said the decision to ban the drug was made despite there being "little or no discussion about how our recommendation to classify this drug would be likely to impact on young people's behaviour. Our decision was unduly based on media and political pressure."
Calls for mephedrone to be made illegal came as a series of reports linked it to deaths across England and Scotland.