Video report by ITV News Political Correspondent Libby Wiener
Conservative MP Crispin Blunt has said reversing free trade agreements with the EU during Brexit negotiations would be "barking mad".
It comes as Theresa May is expected to trigger the start of the Article 50 withdrawal process within days.
Speaking to ITV News Political Correspondent Libby Wiener, Mr Blunt said: "We want to have free trade arrangements with all over the world.
"The European Union is plainly going to be one of those and since we actually have existing free trade arrangements under the single market now, it seems barking mad to me that we reverse back from that position."
The MP, who is chair of the Commons Foreign Affairs Committee, continued: "It's fairly clear what the UK wants in this negotiation, it's much more challenging for the EU 27 [member states] to decide their position and they've got to decide whether or not they want to impose costs on the United Kingdom as a result of us leaving the EU.
"That doesn't seem very sensible to me but politics sometimes trumps economics."
Earlier Mr Blunt's committee warned that failure to reach agreement in the forthcoming Brexit negotiations will be "very destructive" for both Britain and the European Union.
It said there was a real possibility the talks could end with no deal.
But despite the potentially grave consequences, the committee said it had seen no evidence of serious contingency planning by Government.
It said ministers should order all Whitehall departments to draw up a "no deal plan", warning that failure to prepare for such an outcome would be a "serious dereliction of duty".
The Prime Minister has repeatedly said she would rather walk away without a settlement than agree to a "bad deal".
The committee said if all that was on the table was a demand from Brussels for a large lump sum payment with no offer of preferential trading arrangements, that might be the only option.
But given the impact on both sides, it said that it should be a "key national and EU interest" that such a situation was avoided.
"It is clear from our evidence that a complete breakdown in negotiations represents a very destructive outcome leading to mutually assured damage for the EU and the UK," it said.