Angela Rayner's former family home was valued higher than neighbouring properties which went on the market when she sold her share in it to fund the purchase of a lavish seaside flat, it has been claimed.

The former deputy prime mister, who quit the government this morning, sold a 25 per cent stake in the Ashton-under-Lyne property for £162,500 to a trust established for her disabled son earlier this year, based on a valuation of £650,000 for the whole house.

This money was used to fund the apartment in Hove - which led to a major scandal this week when Ms Rayner admitted she underpaid stamp duty by £40,000.

She quit today after an ethics probe found that she breached the ministerial code of conduct, failing ot adequately check she was paying the correct amount.

The £650,000 valuation for the four-bedroom house has already raised eyebrows, as it is exactly the threshold for inheritance tax becoming payable on personal assets.