Environment secretary Theresa Villiers has sought to reassure farmers that high food standards will be protected as the nation seeks international trade deals after Brexit.

Concerns have been raised that food produced to lower environmental and welfare standards than are permitted in the UK will be allowed into this country under future trade deals - undercutting the competitiveness of the domestic agricultural sector.

But Ms Villiers said: "Our strong British brand is built on high standards to which we hold ourselves.

"The high standards of British farming are the backbone of our biggest manufacturing sector of food and drink."

She said the UK could maintain and enhance its standards amid future negotiations with the EU and other countries, and she promised to work with the farming sector to understand their concerns and make sure their voice is heard in international talks.

"Please be reassured, as our manifesto says, as the prime minister has said, we will not imperil our domestic and international reputation built on quality, and grounded in our shared national values," she said.

"We will not dilute our strong environmental protection, we will not dilute our high standards of food safety and animal welfare."

During her speech at the Oxford Farming Conference, the minister also explained plans in the government's Agriculture Bill for a seven-year transition away from EU subsidies mostly paid for the amount of land farmed to a new system of environmental payments for "public goods" such as boosting nature and tackling climate change. That transition is due to begin in 2021. She also confirmed that the current annual budget for agriculture for the whole of the UK - worth around £3.4bn - will be maintained for the coming parliament.

Meanwhile, National Farmers' Union (NFU) president Minette Batters urged the government to introduce a food standards commission that scrutinises future trade deals and helps make the UK a global leader of "climate-friendly food".

Asked if she was convinced by the environment secretary's reassurances, Ms Batters said she wanted to see legislation in the Agriculture Bill that protects UK standards.

"The bit that concerns me is that, if the manifesto commitment is to be honoured, the legislation must be in the Agriculture Bill, it must be set down on the UK statute book in the long term," she said.

In a question-and-answer session at the conference, a straw poll suggested delegates were not convinced the government would defend their interests in international talks.

Pressed on the issue, Ms Villiers said there would be an armoury of tariffs that would make sure that the UK can maintain standards and that imports do not undercut them.