Politicians and legal experts also suggested he must have threatened to take legal action, even as Sir Philip Rutnam, who quit as the Home Office’s top civil servant, pursues a constructive dismissal case.
The departure has been described as mutual, but Meg Hillier, the chair of the Commons Public Accounts Committee (PAC), told The Independent: “It’s clear from this letter and the payoff that Sir Mark was sacked.
“For such a payoff to be considered value for money is clearly comparing it with the cost of a tribunal. It’s easy for the prime minister to sign off such huge sums of money when he’s using the taxpayer’s cheque book.”
And Max Winthrop, a senior employment lawyer, said: “With such a large sum of money being bandied about, it does seem that Sir Mark has been given an inducement to go quietly.
“Employers don’t want someone running off to a tribunal, so they say ‘we will be generous and see you alright’.”
The Independent understands that the NAO and the PAC are automatically asked to look at, and potentially investigate, any such ministerial direction required to authorise such a payment.
The £248,189 has been described as “compensation” for loss of office, although Sir Mark has denied he was forced to resign as cabinet secretary and national security adviser.
It is likely to be paid into his civil service pension pot, the approval letter from the prime minister to the permanent secretary of the cabinet office said.
Sir Mark’s early departure was announced last month after two years in charge, making him the shortest-serving cabinet secretary in history.
On Wednesday, he denied resigning, telling a parliamentary committee: “The prime minister and I agreed I should step down ... because we had concluded it was time to have a separate security adviser and separate cabinet secretary.”
Asked if it was a case of “constructive dismissal”, the prime minister’s spokesperson pointed to Sir Mark’s statements that an agreement had been reached that he step down.
Dave Penman, general secretary of the FDA union representing public service managers, said the sort of “big money” handed over was not unusual for such a highly-paid civil servant.
“The prime minister wanted him to go, so will clearly have to compensate him and justify giving him more than the £95,000 cap on payments.”