The call came on Tuesday, the day the new proposed College of Commissioners was announced.
The new team of 27 commissioners was revealed on Tuesday but excludes the UK, which has not nominated a candidate.Sir Julian King, the current UK commissioner who is in charge of the security dossier, is due to be the last ever British commissioner.
But leaving a vacancy in the week that the UK Parliament has been shut down “would simply reaffirm that Westminster democracy is broken”, said the Scottish MEPs.
Late on Monday, the UK Parliament was suspended for some five weeks amid the latest twist in the ongoing Brexit drama gripping Britain.
The SNP is now calling for the UK to put forward a candidate and insists that any nominee should be a woman to ensure a “gender-balanced Commission.”
The current nominations from Member States so far have resulted in 13 women and 14 men to the new executive.
The UK has a legal right to a commissioner while it remains a member of the EU, which will last until the end of October at the soonest and possibly to 31 January if a three-month extension to Brexit is agreed.
“With the UK Government shutting down Westminster, its refusal to appoint a Commissioner highlights another avenue of representation closed off at a critical time" Alyn Smith, SNP MEP
The SNP says that “failing to nominate would effectively yield huge influence in Brussels at a crucial time.”
Leading SNP deputy Alyn Smith, an ardent Remainer, said: “With the UK Government shutting down Westminster, its refusal to appoint a Commissioner highlights another avenue of representation closed off at a critical time.“
“Leaving a vacancy would simply reaffirm that Westminster is broken and working in no-one’s interests.”
“While the EU is moving forward with progressive, gender-balanced representation, a Westminster Tory Government with no mandate or majority is dragging us backwards - subverting democracy by silencing debate at Westminster and ensuring our voice isn’t heard at the EU Commission either.”
“The SNP will make a final decision on whether to support this Commission after the hearings are complete, but the gender-balanced makeup of the proposed list is a welcome step and builds on progress made by the SNP in government.”
He added, “The UK Government must now step up and fulfil its responsibilities to nominate a Commissioner as an act of good faith in respect of the smooth running of EU institutions. A female candidate would be the obvious choice.”
The following have been proposed for appointment as commissioner:
Helena DALLI (Malta), Valdis DOMBROVSKIS (Latvia), Elisa FERREIRA (Portugal), Mariya GABRIEL (Bulgaria), Paolo GENTILONI (Italy), Sylvie GOULARD (France), Johannes HAHN (Austria), Phil HOGAN (Ireland), Ylva JOHANSSON (Sweden), Věra JOUROVÁ (Czech Republic) , Stella KYRIAKIDES (Cyprus) , Janez LENARČIČ (Slovenia) , Rovana PLUMB (Romania) , Didier REYNDERS (Belgium), Margaritis SCHINAS (Greece) ,Nicolas SCHMIT (Luxembourg), Maroš ŠEFČOVIČ (Slovakia), Kadri SIMSON (Estonia), Virginijus SINKEVIČIUS (Lithuania), Dubravka ŠUICA (Croatia) , Frans TIMMERMANS (Netherlands), László TRÓCSÁNYI (Hungary), Jutta URPILAINEN (Finland) , Margrethe VESTAGER (Denmark) and Janusz WOJCIECHOWSKI (Poland).
Parliament’s former President Josep BORRELL FONTELLES (Spain) has also been appointed High Representative of the Union for Foreign Affairs and Security Policy to replace Federica Mogherini.