Any attempt by the British government to seek full access to European markets without alignment was “absurd” and would be voted down, one of Emmanuel Macron’s top allies in the European parliament has said.

Pascal Canfin, a French MEP who chairs the European parliament’s environment committee, said it would be economically and politically absurd to allow the UK tariff and quota-free access to markets without ensuring it signed up to core EU standards on nature protection, the climate emergency, workers’ rights and state aid.

That would mean “we would give more power to the UK than any member state”.

Although formal talks have not even begun, the MEP said negotiations were not starting on the right path “when you have the UK government saying what I want is full access and divergence”.

“It’s very clear that the scenario that could be favoured by the UK government would be regulatory divergence, but full access to the EU, meaning no-quota, no-tariff, is just a complete no-go, both for the EU team and for the French government.”

The MEP was speaking to journalists after mixed messages from the government over whether it prioritised divergence from EU rules. In separate TV interviews on Sunday, the Brexit secretary, Stephen Barclay, said the UK “will not diverge for the sake of diverging”, while the home secretary, Priti Patel, said “we will be diverging”.

Canfin is a member of an influential MEPs “contact group” that will monitor Brexit trade talks, which are due to get under way in March. The group, consisting of senior MEPs, including those who chair committees on foreign affairs, trade, agriculture and fisheries, replaces the Brexit steering group, led by Guy Verhofstadt, who has been the public face of Brexit for the European parliament since 2016.

Canfin said any deal that failed to uphold core standards would be rejected across the bloc. “If it’s perceived by the politicians, whether at EU level or national level, as ‘unlevel’ and unfair and we give too much access without the UK complying with what is needed then it will be rejected. There is obviously room for negotiation, but not that much.”

The EU insists it will only grant zero tarrifs and quotas in a trade agreement if the UK signs up to a set of core standards, known as the “level-playing field”, to prevent a race to the bottom on environment, worker and consumer protection and state subsidies.

During a series of 11 special Brexit seminars this month in Brussels, diplomats from France, Germany, the Netherlands and Denmark were among those stressing the EU cannot permit being undercut by a competitor not following EU rules.

But it is not settled whether the UK would have to follow Brusselsafter it updates its rulebook.

Throwing new light on the negotiations ahead, Canfin said some areas would require “full alignment”, meaning regular updates with the EU rule book. He cited the example of the EU emissions trading scheme, due to be overhauled in 2021 in order to raise the price of CO2, as part of the bloc’s plans to confront the climate emergency. The EU fears that potentially lower carbon prices in the UK could undermine EU attempts to cut industrial pollution, by depressing the market in emissions permits.

However, the MEP suggested other aspects of the post-Brexit trade deal could be subjected to an agreement not to roll back existing rules, known as “non-regression”.

“Between these two theoretical options: full alignment and non-regression: that’s where the negotiation will take place.”