Long-standing and iconic Brexiteer Sir Bill Cash, along with ERG vice chairman, David Jones, have tabled clauses to the Taxation Bill which appear to have the effect of providing for its supremacy over the Withdrawal Agreement.

In defiance of what Cabinet Office minister Michael Gove has agreed with the European Commission Sir Bill and Mr. Jones tabled two clauses today – similar to those which the Government said it would drop from the Internal Market Bill – designed to assert UK sovereignty over aspects of the Withdrawal Agreement.

No.10 said today it will not be accepting the tabled clauses.

Sir Bill said he was disappointed with No.10’s response and said: “I still believe these clauses are necessary because we still haven’t seen the text of Michael Gove’s agreement in as much detail or analysis as we need. It was unwise to remove them from the UKIM Bill and unwise not to put them in the Taxation Bill.”

Yesterday in the Commons Sir Bill asked for an assurance from the Government “that the necessary measures would be taken in primary legislation if things were to go wrong for the future” which Paul Scully the Minister said he could offer “if it is indeed needed”.

Almost a year ago, when the Government was writing the legislation needed to enact the Withdrawal Agreement, they introduced several clauses Sir Bill had drafted into the Withdrawal Act and which, he had long argued, ensured UK sovereignty as we finally departed the EU and its transition relationship architecture.

The veteran eurosceptic rebel has been conspicuously uncritical of the Government approach in the House of Commons chamber, until now, and has been touted by other senior Brexiteers as being the key to ERG approval.

Boris Johnson’s No 10 political operation has lavished attention on the senior Brexiteer and are convinced that keeping him onside is the key to staving off an ERG rebellion. Sir Bill continues to be supportive of the Prime Minister, saying  “I totally support what the PM is doing and he’s quite right to face down the EU” but since Michael Gove promised that the UK would in fact, as required by the Commission, remove the supposedly “law breaking” clauses from the UKIMB, Sir Bill has been raising open concerns about the impact on UK sovereignty and has requested Michael Gove appear before his European Scrutiny Committee as soon as possible.

Could this be the start of an ERG rebellion against Boris Johnson, of the sort that so tormented Theresa May? It’s noticeable that ERG ire is currently clearly focused on the Cabinet Office minister rather than the PM. This may well suit everyone for the moment. But it’s hard not see the rock and the hard place coming ever close together.