ARTICLE AD BOX
By Chris Mason, political editor and Henry Zeffman, chief political correspondent
BBC News
A top government lawyer warned a plan that would have stopped an incinerator being built in Environment Secretary Steve Barclay's constituency for up to a year was unlawful.
The BBC has seen a legal note compiled within government after consultation with Sir James Eadie KC, the First Treasury Counsel.
It raised "serious concerns of perceived bias" over the issue.
And it warned the decision could be vulnerable to a legal challenge.
The courts might assert that it had been taken "on grounds of political advantage, rather than on legitimate policy grounds," the note added.
Mr Barclay has been a long time opponent of the proposed development in Wisbech in Cambridgeshire.
It would be one of Europe's biggest waste-to-energy incinerators, burning non-recyclable waste in order to generate energy for local industrial use.
Sources claim Mr Barclay was livid at the decision that the incinerator would be built and sufficiently angry that No10 were aware of his fury.
'Correct procedures'
Those around the environment secretary deny that he threatened to resign over it.
He has been recused from any decision on the matter, and a source in the department said "the correct procedures were followed".
Downing Street would not say when Mr Barclay had been recused - the technical term for being excluded from a legal process.
Claire Coutinho's Department for Energy Security and Net Zero gave the plant the go-ahead last month, following a recommendation from the Planning Inspectorate.
But to move ahead, the scheme also requires a permit from the Environment Agency (EA) a public body sponsored by Mr Barclay's Department for Environment, Food and Rural Affairs.
The legal advice offers a view on what it calls "the proposal for an urgent direction to the EA to pause permitting applications for up to a year."
It concludes that this "would be unlawful because the consultation undertaken with the EA was plainly inadequate. The context of the secretary of state's constituency interests and recent public comments adds powerful exacerbating feature given the perception of bias."
Separately, officials escalated the matter to the Cabinet Office's ethics unit, which discussed it with Mr Barclay.
'Political advantage'
The government has said the decision will be taken by a junior minister in the department, Mark Spencer.
The BBC understands Mr Spencer is due to inform the Environment Agency of his ruling in the coming days.
The internal legal note warns ministers of the potential for the decision to be challenged in court.
It says that "it will not escape the notice of potential challengers or the courts" that the idea to delay permitting applications "occurred a very short time indeed" after the decision by the Department for Energy Security and Net Zero to grant permission for the Wisbech plant.
"The strong impression is, and the allegation in litigation will undoubtedly be," the advice states, that any decision not to award a permit to go ahead was taken "on grounds of political advantage, rather than on legitimate policy grounds."
The Prime Minister's Official Spokesman said: "It's not uncommon for ministers to balance their work as a constituency MP with their roles as ministers and there are established processes which support that.
"The government was warned by its most senior lawyer that a plan that would have stopped an incinerator being built in the Environment Secretary's constituency for up to a year was unlawful."