Millions of Barclays customers face turmoil as it battles a fraud case that could see it stripped of its licence to operate.

The lender has been charged over a £7.3bn fundraising drive which saved it from needing a state bailout during the 2008 financial crisis.

It has been claimed that, as part of this fundraising, Barclays illegally loaned £2.1bn to the Qatari state which was then used to buy shares in the bank.

Caught in a storm: Barclays has been charged over a £7.3bn fundraising drive which saved it from needing a state bailout during the 2008 financial crisis

This is illegal under the Companies Act 1985 because it is a form of market manipulation that lets businesses artificially boost their share price. A guilty verdict would leave Barclays open to unlimited fines that could run into the hundreds of millions or even billions of pounds.

The scandal has already seen its former chief executive John Varley, 61 (pictured) and three other former executives charged with conspiracy to commit fraud.

Last year the bank’s holding company, Barclays Plc, was charged with fraud and providing unlawful financial assistance. But yesterday the Serious Fraud Office (SFO) charged operating company Barclays UK Plc – the part of the bank which actually deals with its 48m customers’ money. It will now be tried alongside the other defendants in 2019 and, if found guilty, could be stripped of its banking licences.

It is feared this could leave Barclays unable to handle deposits or make loans in Britain and other key markets such as the US, crippling the institution and plunging its clients’ finances into chaos.

Raising private money to get it through the financial crisis meant that Barclays, unlike rivals Lloyds and Royal Bank of Scotland, was able to avoid needing a bailout. Accepting state help would have given ministers a say over its casino banking operation and multi-million-pound bonus schemes.

Insiders at the bank last night played down the risk of losing its banking licence, saying it remains a distant prospect. Other observers argued that the SFO’s decision is a negotiating tactic aimed at bouncing Barclays into pleading guilty to the charges against its holding company, where a criminal conviction would have less impact on day-to-day operations.

The bank has vowed to fight the claims, as have Varley and the others charged – Roger Jenkins, 62, Thomas Kalaris, 62, and Richard Boath, 58.

A spokesman said: ‘Barclays PLC and Barclays Bank PLC intend to defend the respective charges brought against them. Barclays does not expect there to be an impact on its ability to serve its customers and clients.’

Sources said by the time the case is over, Barclays will have split its UK retail bank into a separate business under new regulations. This may protect the consumer arm from losing its licence even if the regulator decides to act, although the vitally important investment bank would still be hammered.

If Barclays is found guilty, axing its licence would be a drastic step that regulators might decide was against the public interest.

Barclays also faces a £700m lawsuit over the Qatar deal from financier Amanda Staveley, who acted for Abu Dhabi during the same 2008 fundraising and claims she was unfairly treated.

It is fighting a separate case in the US after handling £14bn of toxic mortgage debt during the financial crisis.

Barclays shares rose 0.2 per cent, or 0.42p, to 193.32p in a sign that traders took the latest charging decision in their stride.