MARKS & Spencer's private shareholders are to share in a £2bn cash bonanza under plans which will allow each to decide when they want to take their money.

The high street retailer is handing back 20 per cent of its capital to investors as part of the restructuring promised by chairman and chief executive Luc Vandevelde, in March last year.

Rather than opting to buy back shares on the open market, M&S has decided on a complex scheme that will allow an estimated 358,000 private shareholders to plan when to take the cash and therefore minimise their tax liabilities.

Under the proposed payout, shareholders will be given 17 new ordinary shares and 21 non-voting B shares for every 21 existing shares they hold in the business.

Shareholders will end up owning the same percentage stake in a new holding company, which needs their approval to be set up.

They will also be able to cash in the B shares at a price of 70p each.

The first opportunity to sell the B shares will be on March 25, but M&S said investors can wait until September or any six-month window after that, and take a dividend in the meantime.

Finance director Alison Reed said: ''We'd expect the majority of shareholders to redeem (straight away), but we have set the scheme up this way so they have the flexibility to choose when to take the cash.''

Shareholders needing information on the M&S payout can call a freephone helpline on 0800 035 2780.