He wrote: “Once genetically modified wheat or other crops are commercialised in the UK, what stops the seeds from spreading to the European continent?
“In Europe, winds tend to go from west to east.
“What kind of impact will this have on the biodiversity and wild life, when chemically enhanced and genetically engineered plants take over their place?”
He added: “So far the European Parliament has been the gatekeeper against GMO regulation.
“But in Europe, too, the pressure to allow gene-editing is on the rise. Commercialisation needs not only regulation but the trust of society.
“This is not a given in the EU or UK. Opponents of GMO practices argue that animals and crops modified to resist disease could promote environmentally damaging intensive farming practices.
“A regulatory shift would open up a door and a battle for commercial advances in a post-Brexit world.
“It will be interesting to see whether the sentiment for revenge on Brexit that some politicians are harbouring will override environmental considerations.
A new raft of checks on goods at the ports of Belfast and Larne under the terms of the protocol have sparked anger among unionists who feel Northern Ireland is being separated from the rest of the UK.
Talks are continuing between the EU and the UK Government to solve some of the issues, but many unionists have called for it to be scrapped.
Lord Frost said: “It is clear from the conversations we have had with businesses here today that the way the protocol is operating is presenting various challenges. I’ve heard from business groups how some suppliers in GB are beginning to stop sending products into Northern Ireland.
“We have also heard about reduced availability of choice, cancelled deliveries, products being pulled, interference with movements.
“The protocol relies on cross-community support but this situation does risk undermining that. Our number one priority as the UK Government is protection of the Good Friday Agreement in all its dimensions, north-south and east-west, and that is the top priority of the protocol itself.
“We hope the Commission share that view, although if so they aren’t always as clear about it as they could be.”
Lord Frost added: “The major issue that worries us now is the EU continues to want to treat the regulatory boundary in the Irish Sea as if it were like any other external border, despite the obligations of the protocol to facilitate trade between Great Britain and Northern Ireland, to avoid controls at the ports and airports of Northern Ireland to the most extent possible.
“We are committed to working through the issues with the EU, to find a way forward and have been doing so intensively for the last few months. We have proposed a range of solutions to the existing problems but progress is limited. We do think the EU needs to show more common sense and pragmatism.
“It is hard to see the protocol as currently operating could be sustainable for long and we continue to consider all other options.”