The pension scheme of Uniq, the largest supplier of sandwiches to UK retailer Marks & Spencer, became the food company’s new owner last week. The deal helped plug a £400m black hole in the scheme, saved the company, gave scheme trustees 90% of Uniq’s equity and was the latest example of a trend to prop up schemes by injecting corporate assets.

That trend was started by M&S three years ago when it injected £500m into its pension scheme in the form of a property partnership. The partnership held M&S property, which was then leased back to the retailer, generating income which drip-fed into the scheme.