Concerned farm leaders have lobbied to push back the cut-off date for training and certification from June 1 2016, saying time constraints make the changes "impractical".

Rule changes on how rodenticide is bought and sold are driven by a European Union directive from 2011.

This means farmers can either be UK farm assurance members or possess an approved certificate of competence from an approved training programme after 1 June 2016.

The National Farmers Union, in discussions with the Health and Safety Executive and the Campaign for Responsible Rodenticide Use (CRRU), said delaying the rule change will give the 90,000 agricultural users of rodenticides more “time and flexibility” to undertake training.

NFU President, Guy Smith, stressed the issue of time and the impracticality of fitting training alongside the running of a farm.

He said: “It is essential for many farmers to have access to these products for farm biosecurity and for this reason we have lobbied hard on behalf of our members to secure the necessary additional time and flexibility to reduce this burden.

“Even with this extra time and flexibility it is still important that farmers take practical steps to consider the options that are now available to them to avoid a last minute rush in December 2017.”

The announcement was made on Thursday.