The new boss of NatWest has struck his second deal in little more than a month, buying a £2.5 billion mortgage book from Metro Bank in a further push to expand the lender’s retail business.

The acquisition of the prime residential mortgage portfolio adds about 10,000 customers to the group. It was announced alongside half-year results from NatWest that were better than the City had expected.

The deal comes after NatWest last month agreed to take over most of Sainsbury’s banking business, boosting its assets by £2.5 billion, in what was the first significant strategic move by Paul Thwaite since he was promoted to become the bank’s chief executive.

Thwaite, 51, was confirmed as NatWest’s permanent boss in February, having taken on the role on