Richard Shelby, one of the most important senators in the debate on expensing stock options, has pledged "to go all the way" in his effort to back accounting standard-setters in their bid to force companies to record the cost of options on financial statements.

He has threatened to hold up the entire US federal budget, if necessary.

Mr Shelby, the Republican chairman of the Senate banking committee, said that political moves to override proposed standards jeopardised market credibility and respect for the US globally. Many other advanced capital markets will require the expensing of stock options by companies from next year.

Lavish stock option awards have been blamed for some of the excesses of the late-1990s. Since then the Financial Accounting Standards Board, the US's main standards-setter, has acted to force companies from next year to record the cost of options as an expense on financial statements.

The decision has been attacked by high-tech companies on the US's west coast. They say options are crucial to reward entrepreneurs and staff in innovative companies. Expensing them would severely limit their utility to companies and lead to volatility.

"Political forces . . . are trying to interfere with basic accounting standards," Mr Shelby said. "It's critical that we in the Senate resist the temptation to interfere with FASB."

Technology groups lobbying heavily in Washington have found bipartisan support in the House of Representatives.

A vote is expected in the House in favour of overriding FASB in weeks. Only top executives would have their options expensed with small companies and new public companies exempt. But the Senate, where Mr Shelby and his Democratic counterpart Paul Sarbanes are behind FASB, would have to pass similar measures.

Mr Shelby said he was alive to moves in the Senate to bypass the banking committee. The buzz in Washington is that efforts will be made to attach a FASB override to budget bills that are meant to be passed by House and Senate before the start of the fiscal year in October.

FASB supporters are worried that stock option exemptions would be lost in a mass of details.

Expensing might be sacrificed for items higher up negotiating lists.

Mr Shelby said he was on the Senate appropriations committee that oversees budget talks and was confident he could be on the cross-Congress group that produces a unified budget package.

He said he would fight to remove any FASB override, perhaps stalling the budget's passage by delaying tactics. If the full Senate was asked to vote on a unified bill that included a FASB override, he said, "you could start a filibuster big time on that. We're going to do all we can. We're going to go all the way".