The plans also include new powers to force banks to hand over account information about benefit claimants to help target investigations, echoing a scheme announced by the previous Conservative government.

His was part of a landmark case with two other claimants, where the Court of Appeal ruled that the finance company should pay the hidden commission plus interest back to Mr Johnson.

This morning, lawyers for Prince Harry and former Labour MP Lord Tom Watson, the other remaining claimant, asked Mr Justice Fancourt to delay opening the case twice - meaning the court did not sit until 2pm.

Those settlements left just two claimants - one of them Prince Harry.

However, the party has yet to clarify which benefits it would consider subjecting to means-testing, when the level of support is linked in some way to a claimant's income or wealth.