Ms Hoey dismissed pro-Remain campaigner James McGrory after he claimed the UK economy would suffer from Brexit “knock-on effects”.
Talking to talkRADIO, the Labour MP said: “He talks about the downsides of not being in the customs union but there are huge upsides of not being in the customs union.
“For a start, we would be able to actually import food at a much cheaper price, we would be able to make those trade deals that are going to give us a long-term, better economic future.”
The Brexiteer politician argued against suggestions claiming the British Government had not come up with a viable Brexit strategy, saying Remainers might attempt to use the customs union to keep Britain inside the EU.
She continued: “This idea that we haven’t got any plan: the plan is to leave the customs union.
“The only reason why that keeps being a big issue is because it is being pushed by people who know that if we stay in the customs union of any kind whatsoever we are really staying in the European Union. That’s it, it would be Brexit in name only.
“That is what they really want, many of these people using these so-called economic reasons for pushing that. I don’t see how Theresa May can possibly allow that to happen and I don’t think the country will allow that to happen.”
Theresa May has been facing increasing pressure from pro-Remain MPs and peers seeking to force her to change her Brexit strategy and negotiate with Brussels to create a new customs arrangement with the bloc.
Mr McGrory previously claimed the PM will continue to struggle during Brexit talks because promises made during the referendum campaign had proven to be “undeliverable”.
He said: “The problem that she faces, the Brexit that has been promised to people is fundamentally undeliverable.
“If you come out of the customs union, as the Government is saying that they want to, there are knock-on effects on that. That will have a negative effect on our trade with Europe.
“People have been promised ‘the exact same benefits’ as we enjoy now from membership of the customs union and the single market. That is fundamentally undeliverable.”