Cook has already put aside a sum of £73 million should the Co-operative exercise its “put option” and unwind the deal
that includes 230 Co-op-branded shops.

The option will force Cook to buy Co-operative’s 30% stake in the joint venture. This possibility becomes live from October – five years after the JV was established, and part of a break clause that was included, despite the JV being envisaged as a long-term project at the time.

If the Co-operative Group took this option, an agreement on final purchase and dividend figure would still have to be decided.

Under the terms of the original arrangement Cook agreed to pay the Co-operative total dividends of £37 million by September 2016; so far it has only received £5 million of these, with the remaining £32 million to be added to the final price.

The amount was revealed in the Co-operative’s full-year results, released last week, which also show that the joint venture made a loss of £17 million in 2015.

The news would suggest that it may decide to cash in and split from Cook, although a Co-operative spokesperson insisted to TTG: “No decision has yet been made on this.”

When asked last year about the future of the joint venture, Cook chief executive Peter Fankhauser said: “From our side there is no need and no aim to dissolve this joint venture we have with the [Co-operative] but it’s up to them contractually.”

A source close to the issue said that there would be no impact on Cook’s profits this year, which are expected to be more than £200 million.

But although Cook has made provision to pay the Co-operative, it is still a big black cloud hanging over the group, which could tighten the reins on spending.

The bill for the break-up could also follow a potentially difficult summer for Cook, which has been strongly affected by the removal of Egypt and Tunisia from programmes.

Cook has a 66.5% stake in the joint venture, the Co-operative Group controls 30% and the renamed Central England Co-operative owns 3.5%.

At the time of the merger the three companies controlled more than 1,300 stores, but this has been whittled down. According to Cook’s 2015 annual report, there are only 830 left.

When the deal was announced in 2010 one of its architects, former Cook chief executive Manny Fontenla-Novoa, said it would “unlock significant value” for shareholders.

However, many of the acquired shops were subsequently closed. Fontenla-Novoa left Thomas Cook before the deal could be finalised.