The civil service "would be literally tying itself up in knots" without the rules put in place to govern what support officials can give to ministers who want to leave the European Union, cabinet secretary Sir Jeremy Heywood has said.
Ministers have been allowed to campaign against the government's official position – which is for Britain to stay in the EU – in the run-up to June's in-out referendum, in a break from the usual rules of collective responsibility which require ministers to back the government line.
But guidance issued by Heywood last week made clear that ministers in favour of leaving the EU will face some curbs on the civil service support they receive, sparking the ire of eurosceptics who believe it puts the leave campaign at a significant disadvantage.
Bernard Jenkin: Jeremy Heywood's EU referendum guidance leaves civil servants in an absurd position – he must explain himself to MPs
Nick Pearce: When the government has an agreed position – as on the EU referendum – civil servants must support it
While the guidance says departments should "continue to provide support in the normal way to ministers operating in their ministerial capacity" – it says it "will not be appropriate or permissible for the civil service to support ministers who oppose the government's official position by providing briefing or speech material on this matter".
Heywood on Tuesday faced questions on the rules from MPs on public administration and constitutional affairs select committee (Pacac), which is chaired by the eurosceptic Conservative MP Bernard Jenkin.
Writing on CSW this week, Jenkin argued that Heywood's guidance left the government "in an absurd position", with civil servants "being told to block information to dissenting ministers, despite the fact that the same ministers are constitutionally accountable to parliament for the conduct of their departments".
But the cabinet secretary told Jenkin's committee that the guidance was "broadly the same" as that used in 1975's referendum on whether Britain should stay in the EU's forerunner, the European Economic Community. And he sought to clarify that the curbs would only apply to very specific material.
"There is an official government position, there is official government business. And anyone who is supporting that official government business will get the same civil service support as usual" – Jeremy Heywood
"We don't express it in exactly the same way. But basically it gets to the same point that the material we're not providing to ministers is material that they could use to attack the government position," he said. "And the civil service would be literally tying itself up in knots if it was supporting the government position but also supporting ministers to attack the government position."
Heywood stressed that the rules would not limit the ability of ministers in favour of Brexit to get hold of key facts, or hinder the day-to-day running of their departments.
"All I can say is the spirit of this is very clear," he said. "There is an official government position, there is official government business. And anyone who is supporting that official government business will get the same civil service support as usual.
"In one area alone – in those cases where ministers decide that they want to oppose the government's official policy – the civil service will not be expected to provide briefing material or speech material to support that case against the government.
"I think it would be quite wrong if the civil service was involved in that. It would be a very significant change in the civil service's role in our country. To be actively briefing ministers against the government's policy would be a very significant change and I wouldn't support it and I don't think anybody in the cabinet's asking for that, to be honest."
Iain Duncan Smith not " concerned about where we are at the moment"
Heywood also downplayed a number of media reports that work and pensions secretary Iain Duncan Smith – one of the Cabinet ministers campaigning for Britain to leave the EU – reacted with fury to a request by Number 10 for his officials to provide information relating to the EU, without Duncan Smith's knowledge.
"I haven't read that article," Heywood said. "But I don't think the secretary of state for welfare is concerned about where we are at the moment. I spoke to him about it today. I'm very clear that if he wants to see the statistics that his officials are sharing with Number 10, that's fine. "
The sharing of information between Number 10 and DWP "happens all the time", Heywood said, without ministers "being involved in the slightest".
"But if the secretary of state wants to see some statistical information that his department is providing, of course he can see it," he added.
Jenkin said Heywood had been "very helpful" in confirming that officials could provide pro-Brexit ministers with "any facts" they needed, but he called on Heywood to withdraw the guidance.
"All this guidance and Q&A should be withdrawn and you should produce something much more concise and clear as was produced in 1975," Jenkin told the cabinet secretary. "And then we needn't have had this row."
But Heywood said he did not agree with the need for fresh guidance "at all".
"I think the guidance is extremely concise and clear and we certainly aren't going to be withdrawing it... All I can reiterate is that nobody's having any difficulty with my guidance on the ground," he said.
While DWP minister Priti Patel yesterday hit out at Heywood, accusing him of an "unconstitutional act" in limiting civil service support, the guidance has received the backing of the FDA union, which represents senior officials.
General secretary Dave Penman said: “The FDA welcomes the clear guidance issued by cabinet secretary Sir Jeremy Heywood clarifying the responsibilities of both civil servants and special advisers on the handling of papers relating to the referendum. Civil servants are there to support the government of the day and that government's policies, which in this case is to remain part of the reformed EU."
But he added: “The continued wrangling from politicians over this issue will only serve to impact upon the smooth running of government and damage the essential relationship between civil servants and ministers.”