Customers could be left in a two-tier system that means the better off buy more expensive, British goods while those who are poorer are left with lower-standard cheap imports.
Food Prices and Availability, published today by the Lords' EU Energy and Environment Sub-Committee, warned it was "highly probable" failure to negotiate a post-Brexit free trade deal with the EU would lead to significant price rises for United Kingdom consumers.
Peers said there was a "striking" contrast between Government confidence about the potential impact of Brexit on the price and availability of food and concerns raised by the industry.
This would see the United Kingdom collecting import tariffs on behalf of the European Union - but critics fear it would scupper the UK's ability to have an independent trade policy.
He said: "That agreement is clear".
He wants the Government to negotiate a temporary customs union that will expire in March 2022, three years after the United Kingdom formally leaves the EU. The EU has expressed doubts about whether either option would work. Brexit is turning into a shambolic mess that could not be further from what has been promised. "If current arrangements are not maintained, it is likely the sudden imposition of tariffs and loss of tariff rate quotas would affect the price and availability of food for United Kingdom consumers.". If he continues doing it, what he does is make government impossible.
"The Government has some important choices to make".
"EU food imports can not easily be replaced by either producing more in the United Kingdom or importing more from non-EU countries" the report warned, with United Kingdom self-sufficiency declining over the past 30 years.
He believes the transition should be extended to 2022 to allow time for the technology to be implemented. "It would also take time and, given the restrictions of landscape and climate, there are some foods that could not be grown here".
"It's great to see the progress with the Welsh Government, that they have been willing to accept the latest proposals, and it is a great shame that the Scottish Government has not been willing to do so, but we do hope to be able to do that in due course".
Wetherspoon chairman Tim Martin said: "It is disappointing that the committee has rehashed the scare story that says food prices will rise post-Brexit".
The report added that Britain will struggle to plug any gap left by a decrease on European Union food imports if the costs become too high.
"This will result, as most remain economists have now admitted, in a reduction in food prices in the shops".
Food prices would soar in the event of a hard Brexit, and could ultimately lead to a "two-speed Britain" where poorer people were forced to eat cheaper and lower-quality imported food, a House of Lords report has warned.