Almost 200 submissions are being made in the upper house of parliament as a bill required to trigger the divorce enters its final stages.
On Friday former prime minister Tony Blair launched a movement to try and reverse Brexit but some have dismissed this as arrogant, given the outcome of the referendum.
It’s also being reported that Britain could face the equivalent of R100 billion in extra costs should it leave the EU without a deal.
Government maintains there are no U-turns.
"This bus has left," said one senior EU diplomat.
"No one is happy about it. But we have moved on and the last thing anyone wants now is to reopen the whole issue."
Some still talk of hope: "Despite the hard rhetoric and threats by the British government ... the European Union remains a project of mending," said German lawmaker Terry Reintke, who speaks on Brexit for the Greens in the European Parliament.
