Plans to legalise cannabis so it can be taxed and sold on the high street will be brought forward if the Liberal Democrats gain power.
The party will commit to creating a legal market for the production and sale of the substance in its manifesto, it confirmed, making it one of the first political parties to fight an election on a ticket of relaxing drug laws.
Cannabis would only be sold to people over 18 and sales would be strictly regulated under the new proposals, which could generate up to £1 billion per year in tax revenues, the party predicts.
The Lib Dems have long campaigned to legalise the drug, with former health minister Norman Lamb attempting to bring in a Bill last year to tackle what he called "a catastrophic failure" of the war on drugs.
Another manifesto commitment would offer fathers an extra month of paid parental leave, to encourage greater sharing of parental responsibilities.
Former minister Jo Swinson said: "Parents across the UK have already benefitted from greater flexibility and freedom in how they share the care for their new baby.
"But more needs to be done in order to encourage men to take leave when they become a dad, to bond with their child during the early weeks and months of their life."
The party said funding of the measure would be outlined in the Lib Dem manifesto, which is due to be published in the coming days.