It comes as MPs have overturned measures aimed at protecting UK food standards in future trade deals, despite a Tory backlash in the Commons.
They voted 332 to 279 in favour, a majority of 53, to disagree with a House of Lords amendment to the Agriculture Bill, which would have required agricultural and food imports to meet domestic standards.
Peers had made the change to block the import of foodstuffs produced abroad with lower animal welfare standards, amid warnings over chlorinated chicken or hormone-treated beef entering the UK market from the US.
Several Conservative MPs also outlined their support for the amendment as the Bill returned before the Commons for further debate.
But it was stripped from the Bill following a vote on Monday. The Government argued existing protections were already in place and they had no intention of watering them down.
Oliver Cartwright, NFU spokesman, said: “The NFU and Shropshire farmers are fully committed to ensuring British farming’s high standards are not undermined by imports of food produced to standards that would be illegal here.
“The call for action continues and we have seen a huge wave of public support, organised a hugely successful petition with more than a million signatures and seen mass MP lobbying on this issue.
“We believe this is currently the best route to make our voice heard among MPs and decision makers given the current situation with Covid-19.
“The Agriculture Bill now returns to the House of Lords, following Monday’s vote in the Commons, and we will continue to make the case for our industry – we need a binding commitment that our standards will not be compromised.
“Shropshire farmers produce great product food and drink that is affordable and traceable and produced to high standards that county shoppers demand.
“Government needs to give some certainty to businesses trying to plan for the future and we can’t simply open our doors to the rest of the world without checks.
“We would urge everyone – producers, processors, politicians, retailers and shoppers – to back British farming like never before.”
Prior to the vote, farmers demanding that food standards are upheld in post-Brexit trade deals made their voices heard during a tractor demonstration in central London.
The agricultural vehicles assembled at New Covent Garden from 1pm on Monday as part of a protest planned by campaign group Save British Farming.
They then headed for the Department for Environment, Food and Rural Affairs (Defra) and Parliament Square in Westminster as MPs prepared to vote on the amendment to the Agriculture Bill proposed by peers.
Speaking as Lords' amendments to the Bill were considered, senior Tory Neil Parish said the legislation was heading in the right direction but the UK should be a "great beacon" on animal welfare and the environment when negotiating future trade deals.