The bloc’s chief negotiator said he was prepared to “listen” to the Labour leader and Scottish first minister but that what they say will have no bearings on how the negotiations pan out.
Mr Corbyn, Ms Sturgeon and Welsh first minister Carwyn Jones are all travelling to the Belgian capital tomorrow to hold meetings with Mr Barnier about the progress of the talks.
But the Frenchman was distinctly unenthusiastic about the prospect of meeting the trio, saying he was only holding the three-way conference because they had asked for it.
Speaking to reporters Mr Barnier also had strong words for Britain over the issue of paying a Brexit bill, saying ministers’ refusal to accept financial commitments was damaging trust between the two sides.
He told reporters: “I have always made it clear that I want to listen to the different points of view in the British debate, it is only natural.
“Tomorrow I will meet, at their request, Jeremy Corbyn and Nicola Sturgeon and Carywn Jones. Of course I will only negotiate with the UK Government.”
Speaking at a press conference in Brussels the bloc’s chief negotiator also had a brutal putdown for foreign secretary Boris Johnson, who said this week the EU could “go whistle” over its demands for an £80 billion divorce bill.
He said: “On the financial settlement it is essential that the UK recognise the existence of financial obligations. I’m not hearing any whistling, just the clock ticking.”