Bradford & Bingley shares crashed 19% or 15½p to an all-time low of 64½p today, after Clive Cowdery dramatically threw in the towel on his plan to inject £400 million into the company instead of its planned rights issue and share placing.

Cowdery, the man who made £150 million from restructuring the life insurance industry, accused B&B of obstructing all his attempts to put his plans forward.

He said: "The entrenched position of the board of B&B has prevented the constructive engagement necessary to finalise this proposal.

"Given this, Resolution believes it cannot responsibly continue to recommend this proposal to B&B's investors."

A clearly aggrieved Cowdrey said he still plans to be at the forefront of plans to bang together smaller banks and lenders in the UK.

But there was speculation in some parts of the City that Resolution may have run into trouble with regulators over its plans for B&B. It is known that the FSA is closely involved in B&B's own bailout plan.

Investors in B&B were likewise angry that the former building society had refused to open its books to Cowdery.

B&B's biggest shareholder, Standard Life, went on the attack against the board tonight. The giant fund said it was concerned that the board was not more responsive to Resolution's proposal.

A statement from the Standard Life added: "It would have been in the best long-term interests of B&B shareholders for the board to have enabled Resolution's proposal to progress."

For its part, B&B issued a statement saying the board had fully considered the Resolution proposal but was concerned that the plan amounted to Cowdery's firm taking effective control of the bank. That factor was not reflected in the terms of his proposals, B&B said.

The board was also concerned about the lack of definite details about the funding and ownership structure. It urged shareholders to back its own plan for a recapitalisation fronted by Texas Pacific.

Cowdery had the backing of four of the largest shareholders - Insight, Standard Life, Prudential and Legal & General - when he first approached B&B.

Since then, Resolution claims to have won round institutions owning 25% of the bank and the UK Shareholders Association, which speaks on behalf of B&B's 930,000 private shareholders.

Investors have been vociferous in the outrage at B&B's plans to sell a 23% stake to US private equity group Texas Pacific for £179 million without giving them the right to clawback their entitlement to new shares.

Instead, they can only subscribe to the £258 million rights issue at 55p a share and will be automatically diluted down.

Today Cowdrey said his plan restored such pre-emption rights, had the " overwhelming support" of investors, offered a higher price of 72p a share and had a clear strategic direction.

But after one of the shortest battles in corporate history - it lasted just 13 days - Resolution appears to have been frustrated by the B&B board.

B&B has already been forced to scrap one rights issue after its shares fell below the offer price. It returned with another cut-price one and the unexpected interjection of Texas Pacific.

B&B told its shareholders today they now had to vote for both the rights issue and the Texas Pacific cash injection to go ahead at a meeting a week next Monday.

Sources close to the private-equity group said it had always been the only serious deal on the table which offered stability to the bank.

B&B said that Cowdrey had failed to answer several basic worries that it had over his proposals, notably on his funding and commitments, as well as the potential change of control of the bank.