The NFU has called on the new government to set out clear 5-a-day campaign goals and explain how they will be achieved.

Consumers now understood the message, but a clear approach with measurable goals was needed to increase consumption, NFU horticulture board chairman Sarah Pettitt told last week's Re:fresh conference.

"The 5-a-day mantra is now firmly established in the psyche of the consumer," she said. "What we need to do now is turn that into behavioural change."

One approach could be to tax unhealthy foods, she said. "If we are going to promote an increase in fruit and vegetable consumption perhaps we too must consider the unthinkable in terms of intervention."

Another speaker, Pam Lloyd of Pam Lloyd PR, criticised the government's "lecturing, hectoring, shaming" approach to 5-a-day marketing, claiming it should instead seek to "inspire and educate".