•The National Farmers Union said without a Brexit deal its members face tariffs on exports while overseas rivals will not be taxed
•Also, some clothing shipped into the UK will be taxed at between 8% and 12%
Farmers will feel "betrayed" by a government plan not to impose tariffs on the majority of goods entering the UK in the event of a no-deal Brexit, the National Farmers Union has said.
The government has announced it will not tax 88% of imports into the UK.
The NFU said without a Brexit deal its members face tariffs on exports while overseas rivals will not be taxed.
"The prime minister has missed a real opportunity to back British farmers," said NFU chief Minette Batters.
The government published its updated proposed tariff regime ahead of the UK's scheduled departure from the European Union on 31 October.
The regime, which will apply for the first year after the UK leaves the EU, contained three amendments including adjusting tariffs on bioethanol imports.
Also, some clothing shipped into the UK will be taxed at between 8% and 12%.
Both revisions are aimed at protecting domestic bioethanol and clothing producers from cheaper imports.
Earlier this year, the government said it would introduce tariffs on some meat and dairy products shipped into the UK following a no-deal Brexit.
However, its latest plans indicate 88% of UK imports will be tariff-free if the country leaves the EU without a deal, up from 87% announced in March.
Ms Batters said: "We will see, from day one, farm businesses facing new, high tariffs on much of the 60% of our exports that go into the EU, while tariffs on goods coming into the UK will be set far, far lower and in many cases won't be applied at all."
She added: "Farmers are going to feel betrayed by this government's failure to act now in making sure that all that can be done is being done to help mitigate the damaging effects of a no-deal Brexit."
Dairy UK, the trade body, said it had told the government earlier this year that "this major liberalisation did not offer the level playing field this industry needs to survive".
"Our preference is a deal," said Dairy UK's chief executive Judith Bryans. "One which allows us to have open frictionless trade with our largest export customer, the EU.
"If that doesn't happen, the government needs to impose reciprocal tariffs to level the playing field and put in place a package of mitigation measures, before businesses are pushed to the wall."
Trade Policy Minister Conor Burns, said: "Our temporary tariff regime will support the UK economy as a whole, helping British businesses to trade and opening up opportunities for business to import the best goods from around the world at the best prices for British consumers."
Free market think tank the Adam Smith Institute said: "British farmers can compete with the rest of the world on price and quality, they shouldn't be crying betrayal at the prospect of ministers no longer taxing British consumers for daring to buy things from abroad.
"Freer trade was a key benefit of Brexit, and we should celebrate the removal of tariff barriers across the economy."
The Department for International Trade also announced on Tuesday that a proposed 22% tariff on lorries sold into the UK would fall to 10%.
Lorries sold to the UK are currently not subject to a tariff, something the Road Haulage Association said should continue in the event of a no-deal Brexit.
RHA chief executive Richard Burnett said: "The original proposal of a 22% tariff on HGVs coming in from the EU was unbelievable.
"A 10% tariff will still be crippling and will severely damage the lives and livelihoods of those responsible for operating the very industry that keeps the UK fit to live in."
Commenting on the change to lorry import taxes, Meredith Crowley, an economist specialising in international trade from the University of Cambridge, said the UK's heavy goods vehicle sector was facing "some difficulty with Brexit".
She said: "They were trying to have the same high tariffs on imports from the European Union but that could also raise prices for purchasers of heavy goods vehicles."
"These vehicles are really expensive, so £85,000 to £100,000."
Meanwhile, a government paper on Monday found UK and EU firms would be faced with a "a significant new and ongoing administrative burden" in the event of a no-deal Brexit.
It found large firms importing and exporting at scale would need to fill in forms taking one hour 45 minutes on average and cost £28 per form for each load imported.
Separately, in a new 155-page "Brexit readiness report", the government said that a new advice service to help suppliers of medical goods would be launched.