American regulators have allowed the cultivation and sale of two crops modified with the gene-editing technique known as Crispr. The crops – a white button mushroom and a form of corn – are the first Crispr plants to be permitted for commercial use in the US.

The move is a boost for new technology in the creation of foodstuffs, but is expected to worsen the considerable confusion in Britain over the use of gene-editing in agriculture and the importing of crops created using such technology.

A committee of European commission regulators was expected to report last month on whether gene-edited crops should be classed as genetically-modified organisms or should be freed from the severe restrictions concerning GMOs in Europe. At the last minute it announced a delay in its verdict – to the dismay of many UK scientists.

“The committee knew it would be highly controversial, no matter what decision it made, so they have kicked the issue into the long grass, and that is very damaging,” said crop scientist Professor Huw Jones of Aberystwyth university.

“Researchers and plant breeders in the UK simply do not know whether it is worth investing time and money in creating novel foods using gene-editing, despite its enormous potential. At the same time the US has given clear signals of approval to its scientists.”

Button mushrooms can now be ‘edited’ in the US. Photograph: Alamy

Gene-editing is the biological equivalent of the find-and-replace function on a word processor. First, it locates a gene to be edited, then it makes the necessary change, either by deleting or repairing it. This has made genetic modification a dramatically simpler process. Instead of inserting a completely new gene from another organism into a plant’s chromosomes – genetic modification – the new technique merely fiddles with the crop’s existing DNA to create novel strains. As a result it is virtually impossible to differentiate between a crop strain created by traditional breeding techniques and those involving gene-editing.

Several gene-editing techniques have been developed, but Crispr is now rated the most promising. Most scientists believe gene-editing could play a major role in improving crop yields, though the green movement disagrees. Its activists have trashed trials of GM plants, and consider gene-editing to be very similar. They say crops created in this way should be kept within the EU’s highly restrictive GM regulatory framework.Such an interpretation has been rejected in the US, where the button mushrooms have been gene-edited to resist browning on the shelf, and the corn – known as a waxy corn hybrid – has been altered to improve yields.

Crispr holds great promise for maintaining the world’s ability to produce an abundant and healthy food supply Neal Gutterson, DuPont Pioneer

“As an advanced plant-breeding tool, Crispr holds great promise for maintaining the world’s ability to produce an abundant and healthy food supply,” said Neal Gutterson of DuPont Pioneer, creator of the gene-edited corn.

In Britain, scientists have developed a number of promising plant strains but still do not know if they will be treated as GM crops, effectively blocking their cultivation. Examples include research at the John Innes Centre, outside Norwich, where scientists have created barley that can make its own ammonium fertiliser – a major bonus for nations with poor soil – and another group has developed a beetroot that can produce L-Dopa, a drug used to treat Parkinson’s disease. Both groups are still waiting to hear from the European commission if commercial cultivation of their products will one day be allowed.

It is also not clear whether importation of products such as gene-edited corn will be allowed into Britain or the rest of Europe, because the commission has not decided whether it is to be rated a GM crop or not. This could trigger awkward problems with food labelling in coming years.

“It is very frustrating that we have no guidelines whatsoever from the European commission, despite the length of time it has had to consider what is, after all, an enormously important issue,” said Penny Maplestone, chief executive of the British Society of Plant Breeders.