Emergency measures to protect the UK against further introductions of oak processionary moth came into force yesterday.

The action, an amendment to the Plant Health (Forestry) Order 2005, will require that all oak trees imported from the EU are accompanied by a “plant passport”, regardless of whether they are prepared and ready for sale to the final consumer.

Roddie Burgess, head of plant health at the Forestry Commission, said orders for oak trees placed with suppliers in EU countries where the moth is present, including Holland, France and Italy, would be particularly affected.

The commission has also asked the European Commission to draft further protective measures, likely to result in the UK becoming a “protected zone”.

Meanwhile, the Forestry Commission is stepping up its efforts to eradicate the moth from parts of west London where it has been breeding.

Oak processionary moth caterpillars are labelled forest pests because they feed on oak leaves, while their tiny hairs are barbed and carry a toxin. GPs and other health professionals in west London are being warned in case people come into contact with hairs.