Meanwhile, the prime minister’s independent adviser on ministerial standards, Sir Laurie Magnus, will now have the power to launch investigations into alleged breaches of the code without seeking the consent of the prime minister.
Previously the PM was able to veto investigations by the adviser.
The change was promised in Labour’s election manifesto.
The ministerial code sets out the standards that ministers are expected to uphold.
While Sir Laurie advises the prime minister on adherence to the code, Sir Keir has the final decision on whether there has been a breach and what sanctions, if any, are required.
In a forward to the code, Sir Keir said: “For a long time, [the British people] have looked at the conduct of politicians in Westminster and not seen the high standards of public service they expect or deserve.”
He added that the updated code “sets out the higher standards that the British people expect and that ministers must now follow”.
