It would be enough to buy Tesco twice over. Or Barclays, with almost enough change left over to buy Lloyds as well. Even by the standards of the financial markets 50 billion Swiss francs (£45 billion) is a lot of money. And yet, as it turns out, it is not enough to save Credit Suisse.

The Swiss government is searching around increasingly desperately for a way to fix the embattled bank, including this weekend a merger with its traditional rival UBS. But in the end it now looks inevitable that it will have no choice but to take it over and wind it down in the most orderly way possible. Credit Suisse is beyond rescuing.

In reality, it is hard to see that Credit Suisse has any future left

With rumours of its impending collapse swirling through the markets last week, the Swiss National Bank finally decided it had no choice but to step in with a rescue plan, On Wednesday night, it offered the bank a Swf 50 billion lifeline, enough money it hoped to prop it up while it management tried to work out a way of rescuing it. It was a lot of money, almost 6 per cent of Swiss GDP, or double the amount that Gordon Brown committed to rescuing the Royal Bank of Scotland during the financial crisis of 2008 and 2009. And yet, within a day the rescue was already unravelling, with Credit Suisse’s shares tumbling once again. On Friday, the shares fell another 10 per cent and were back close to the mid-week lows.

This weekend, the Swiss government and regulators are trying again, with reports of a merger with UBS. It may be forced into rescuing its rival, but it is clearly being hustled into the deal, and shows no enthusiasm for it. After all, UBS could have bought Credit Suisse at any point over the last five years if it wanted to. Zurich, where both banks are headquartered, is a smallish town, and it is safe to assume that UBS’s senior executives know enough about the state of their rival not to go anywhere near it if it can possibly be avoided. Indeed, UBS’s shares were also down by 10 per cent last week, as investors started to grow nervous that it might be made to sort out the mess.

In reality, it is hard to see that Credit Suisse has any future left. Once confidence in a bank evaporates, it is virtually impossible to ever win it back. With years of scandals and mismanagement behind it, Credit Suisse has clearly run out of time. Even a 50 billion lifeline from the Swiss central bank has not been enough to save it.

A merger with UBS will be the last throw of the dice. If that fails as well, as it well might, there will be few options left other than a full state takeover, and a gradual winding down of its operations. It will be hugely expensive for the Swiss state, and will end up costing a lot more – but trying to keep it alive no longer looks like a realistic option.