A review ordered by Boris Johnson in response to concerns over David Cameron’s lobbying attempts has called for a strengthening of the rules.

The second part of the long-awaited report by Nigel Boardman was published on Thursday and called for a variety of reforms in the wake of the Greensill scandal.

Mr Boardman noted that if his recommendations were in force at the time, then, the Conservative former prime minister would have been required to register as a lobbyist.

The review was launched in April after it emerged Mr Cameron privately lobbied ministers to attempt to try to secure access to an emergency coronavirus loan scheme for Greensill Capital.

Mr Boardman recommended that the “transparency of lobbyists be strengthened” by requiring them to disclose the ultimate person paying for, or benefiting from, their work.

Lobbyists should also meet a statutory code of conduct setting minimums standards, he advised.

Mr Boardman added that former ministers have “a privileged position” derived from their work in Government and called for the Register of Consultant Lobbyists to include any former minister or senior civil servant who undertakes any lobbying activity.

“I note that, were these recommendations in force at the relevant time, Mr Cameron would have been required to register as a lobbyist,” he added.