The NHS’s leadership was “bloody stupid” to expect an emergency £4bn cash injection in last month’s budget, the official who until last week ran the service’s financial regulator has said.

Ministers will additionally have been “pissed off” with the “negativity” shown by NHS leaders such as Simon Stevens towards the £1.6bn settlement the health service ultimately got from the chancellor, Philip Hammond, according to Jim Mackey.

The remarks by Mackey, who stepped down last week at the end of a two-year secondment as the head of NHS Improvement, suggest divisions at the health service’s highest levels over how it should seek to obtain more money.

Stevens, the chief executive of NHS England, made clear in a hard-hitting speech before the budget that the service needed to receive at least £4bn additional funding in 2018-19 in order to cope with all the demands being placed on it.

It ended up receiving £2.8bn more over three years, including £1.6bn for next year, as well as £3.5bn separately over four years for capital projects and also a government commitment to fund a pay rise for staff.

“We’ve got an investment that none of us think would be enough, and none of us should have thought we’d get enough because that would just be frankly bloody stupid, but we’ve got a serious investment and we’ve got to get the best out of it,” Mackey told the Health Service Journal.

Soon after the budget on 22 November, both the NHS England chairman, Prof Sir Malcolm Grant, and its medical director, Prof Sir Bruce Keogh, made clear in public statements that £1.6bn was too little.

The government’s decision meant that “we can no longer avoid the difficult debate about what it is possible to deliver for patients with the money available”, said Grant. Keogh warned that the £1.6bn would “force a debate about what the public can and can’t expect from the NHS. Worrying that longer waits seem likely/unavoidable.”

NHS England has since made clear that patients will have to accept even greater rationing of healthcare because the service can no longer afford to provide all the care that patients need.

But in his HSJ interview Mackey claims that such statements will have alienated ministers and made it harder for NHS bosses to secure access to them.

“If I was ... the chancellor or prime minister and you put that kind of money in and all you get is negativity, I’d be really pissed off,” added Mackey, who has returned to his previous role as chief executive of the Northumbria Healthcare acute trust.

“There’s a danger that we’ve talked ourselves out of the game and we’ve got to regroup on that quickly,” he said. However, he agreed with Stevens, Grant and Keogh that £1.6bn was too little. “The new money ... can’t mean we deliver all of the standards and balance the books and invest in mental health and primary care and cancer and all those things – it’s not enough to do all that.”

Mackey was admired by Theresa May for his efforts to tackle the health service’s £2.5bn-a-year deficit – and get it to stay within the budget the government had given it. Despite his background as an NHS trust boss, he pushed through some measures to try to restore financial discipline, such as “control totals” for hospital trusts.

His comments came as NHS Improvement placed King’s College Healthcare NHS trust in London into “special measures” because its projected deficit for this year has ballooned from £38m to £92m.

The move follows the unexpected resignation on Sunday of that trust’s chairman, Lord Kerslake, a former head of the civil service, in protest at what he claimed was government underfunding. Kerslake is being replaced by the businessman Ian Smith.

“We understand that the wider NHS faces financial and operational challenges, and other trusts and foundation trusts have large deficits. However, none has shown the sheer scale and pace of the deterioration at King’s,” said Ian Dalton, Mackey’s successor.

The NHS Confederation, which represents most hospital trusts, said it shared Kerslake’s view and that the NHS needed an extra £4bn in each of the next two years. Labour and the Liberal Democrats also voiced their support.

In a statement the trust said: “All our services will continue to run as normal. We take NHS Improvement’s decision very seriously and are on track to deliver significant savings in this financial year. We look forward to working closely with NHSI to reduce our deficit and improving our financial position.”