Danuta Hübner, the chair of the European Parliament’s Committee on Constitutional Affairs, said there will be no “cherrypicking” European policies once Britain leaves the bloc.
The warning echoes those of German Chancellor Angela Merkel and other European Union leaders, who have voted to take a hardline stance with Theresa May in the upcoming EU exit talks.
Speaking to EURACTIV.com, Ms Hübner said: “In Europe, everything is linked.
“If you are part of the single market, you have to be subject also to the jurisdiction of the European Court of Justice, you have to contribute financially, and you have to respect our values.”
Danuta Hübner insisted the UK needed to accept European values for single market access
The Polish MEP suggested all of the “lies” and “false information” peddled during the EU referendum campaign had no place during the Brexit talks.
Ms Hübner made it clear the Remain camp in Britain needed to be taken into account during the negotiations.
She said: “I hope nobody is looking at this process, even as difficult as Brexit is, through the eyes of Mr [Nigel] Farage.
“I hope that people can see that negotiating will be a learning process for everybody.
“Europe will be seen by the British citizens and European citizens in the right context at a process which is damaging… but to which we have to find an agreement.
I hope nobody is looking at this process through the eyes of Mr [Nigel] Farage
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“That is the will of the people so let’s do it so nobody suffers.”
Ms Hübner also weighed in on the UK’s future relationship with Ireland, an EU member, saying a hard-border was “a risk that we have to take into account”.
She added: “Those people who have been in peace for many years they don’t deserve [strict borders].”
The Polish MEP argued that border issues would “require a special approach”, she said: “it would be a shame for Europe” if an agreement could to be reached.”
In pictures: Theresa May meets with EU's Tusk Thu, April 6, 2017
The two leaders held talks on Brexit negotiations
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European Council President Donald Tusk gestures to members of the media as he leaves 10 Downing street after talks with British Prime Minister Theresa May in central London
She continued: “You have the Good Friday agreement, but you also have very personal links… It’s not only political stability, or lack of it, but it’s also regional cooperation which Europe has invested a lot.
“Of course there is a possibility of finding a technical solution, which would allow the people there to live, to work and to continue what they have built and achieved so far.
“We have heard already from some prominent politicians that there is also a political solution, it is not just up to European Union to support those options.
“We will do everything to avoid that a really hard-border is created.”