The chancellor has raised the possibility of a big upheaval to inheritance tax less than a year after George Osborne’s reforms came into effect.

Philip Hammond has written to the Office of Tax Simplification (OTS) asking for a review, describing the present regime as “particularly complex”.

The letter raises the possibility that generous reliefs that can be used to mitigate inheritance tax (IHT) bills may be limited or removed entirely.

It may also be seen as a rebuke to Mr Osborne, who added another layer of complexity to the tax by introducing an extra IHT-free threshold for people who leave a main residence to a family member. The changes, announced in the budget of 2015, are being phased in and will eventually mean that parents