The link to the Independent says:
Boris Johnson is to strip the Electoral Commission of the power to prosecute law-breaking, just weeks after it launched an investigation into his controversial flat refurbishment.

The watchdog has been threatened with curbs ever since it embarrassed senior Tory figures by fining Vote Leave for busting spending limits for the Brexit referendum.

I do wonder why "The Electoral Commission", a body responsible for "integrity and transparency of party election finance" was conducting an inquiry into the payment for the PM's flat.
Possibly claims that they are a party political body, and acting beyond their remit, are correct.
Their action against "Vote Leave" following the referendum was judged by the High Court to have been because Vote Leave acted on guidance given to them by The Electoral Commission themselves.