Under the Weeds Act 1959 the Secretary of State has the power to issue an enforcement notice requiring an occupier or authority, responsible for land on which ragwort is growing, to take action to prevent it spreading to neighbouring land. If an occupier has unreasonably failed to comply with an enforcement notice, the Secretary of State may take action to arrange for the weeds to be cleared and recover the cost of doing so. The Weeds Act was amended by the Ragwort Control Act 2003, which provides for the publication of a code of practice for managers of land on how to prevent the spread of ragwort.
Defra's policy under the Act is to investigate complaints about injurious weeds where there is a risk of spread to land used for horses and other livestock, for the production of conserved forage or for other agricultural activities, and where the complainant has already made an attempt to settle the matter informally. Defra's policy is to control rather than eradicate ragwort and other injurious weeds, as it is recognised that both make an important contribution to the biodiversity of the countryside.
Natural England investigates complaints under the Weeds Act on behalf of Defra and will investigate complaints in relation to common ragwort growing on the sides of roads, where the above criteria are met.