The head of the Government task force looking into the elimination of peat use in the UK, Dr Alan Knight, has ruled out taxing peat imports during a BBC Radio 4 You & Yours discussion.
He agreed that peat alternatives would be more expensive because of higher manufacturing costs, which would prompt more imports and damage UK businesses.
However, when presenter Winifred Robinson suggested a tax on peat coming into the UK, Knight said the problem was "you then start penalising foreign growers", which angered some listeners.
Stockbridge Technology Centre chief executive Graham Ward responded: "Knight seems very concerned about penalising foreign growers but the Defra policy will kill off horticulture so what about some concern for English growers?
"Growers have been trying for 20 years to reduce peat use and have made great strides. Without agronomic or financial support, our sector will be subjected to unfair price competition."
Boningale Nurseries managing director Tim Edwards said: "I think Knight is aware of the pragmatic issues. But I don't believe English bogs are any longer at risk - the important ones have been identified and safeguarded.
"There's lots of emotion and not much evidence-based data on the argument for a ban. Recent Defra information is farcical, suggesting peat in lorries pushes up carbon footprints but ignoring that coir from Sri Lanka has to be shipped and lorried."
Horticultural Development Company chair Neil Bragg added: "My interpretation (of what Knight said) is that if you tried to put a tax on plants in peat from other member states this would penalise them from exporting and this is not allowed under EU law on trade."
Johnsons of Whixley joint managing director Andrew Richardson said: "Virtually all of the industry's research base has disappeared.
"I was in meetings on behalf of the HTA with the Government and without doubt much of the science behind the wish to do away with peat is flawed. It is crucial some of our independent research base is put back in place with proper funding."
Peat ban Dutch industry dismisses impact
Dutch trade body Royal Trade Association for Nursery Stock & Flower Bulbs (Anthos) has said it is unlikely that the targets set by Defra for the phase-out of peat would be met.
Anthos secretary Matthys Mesken said an England-only ban would not be possible under EU law and many countries would veto an EU-wide policy.
He added: "I'm not sure whether it's possible for professionals to grow effectively in peat-free media, so it will be up to individual retailers and their suppliers to decide. This is not an issue in the Netherlands."