Under the EU withdrawal agreement, there should have been an established joint assembly with 35 members from each side to oversee issues caused by Britain’s withdrawal, such as the Northern Ireland protocol.
With the European Parliament ready to go, the SNP’s foreign affairs spokesperson Alyn Smith has now urged the UK Government to speed up the process.
He said: “This Parliamentary Assembly should have been set up long since. It will be vital to keep an eye on the many problems Brexit has caused and hold the UK Government and indeed EU Commission to account where right now we have an unelected unaccountable Lord representing the UK, seemingly running amok unchecked.
“We are already seeing the impact of Brexit and the UK Government needs to be doing more to address these issues.
“It is really important that we do not drift away from the EU mainstream and this forum will, I hope, be vital in identifying problems before they become crises.
“The European Parliament has set up their side. The UK dragging their feet to this extent can only be to avoid scrutiny and it is a poor show.”
The Scotsman understands the EU was happy with the speed of the initial talks.
The head of the European Parliament Liaison Office, Susanne Oberhauser, said: "The European Parliament attaches great importance to the setting up of the EU-UK Parliamentary Partnership Assembly.
“As soon as the ratification of the TCA was completed at the end of April, contact was made between the president of the European Parliament, the Speaker of the House of Commons and the Lord Speaker of the House of Lords regarding the modalities of setting up this assembly, in particular as regards the size of the assembly.
"The European Parliament is now looking forward for the UK side to finalise their internal procedures and to set up their delegation, so that the Parliamentary Partnership Assembly can have its first constituent meeting in the next couple of months.”
The UK Government did not respond to requests for comment.