Robert Jenrick, the shadow justice secretary, yesterday questioned whether judges who had previously supported or volunteered for charities providing free legal advice to migrants could be considered “neutral and unbiased”.

In an article for The Telegraph, he singled out Bail for Immigration Detainees (BID), a registered UK charity which last week said it had received online abuse and threatening emails after a front-page story in the same newspaper.

BID says it aims to end immigration detention in the UK through the provision of legal advice, information and representation alongside research, policy advocacy and strategic litigation.

Mr Jenrick claimed that more than 30 sitting immigration judges “have former links to the very activist groups that have ground our court system to a halt”, which he said was evidence of “a judiciary where activism and adjudication seem to go together”.

He said judges who undermine public confidence in the impartiality of the judiciary “should have no place in our justice system”.

The Conservative Party is now proposing to effectively undo the creation of the Judicial Appointments Commission and the Judicial Conduct Investigation Office.

Mr Jenrick said judicial appointments should again be made directly by the justice secretary, supported only by a new “vetting board” to “scrutinise their background for any sign of bias, of whichever political hue”.

He also claimed that a reformed conduct regime would mean “biased judges will be sacked automatically”, while Westminster could “invoke its ancient power to remove judges from the senior courts” if necessary.

“These reforms aren’t radical; they restore the position we had in this country before Blair’s constitutional vandalism,” he said.

“But to members of the judiciary who object, let me say this. If you had kept your house in order, there would have been no need for these reforms.

“The public expects the courts to be impartial. Nothing less is acceptable.”