US hedge fund, Coltrane Asset Management, has tabled a second plan and gone on the attack demanding directors stop prioritising discussions with lenders at the expense of shareholders.

The latest move comes after Interserve’s board dismissed Coltrane’s earlier proposals as undeveloped and recommended shareholders accept a revised plan.

A spokesperson for Coltrane said: “Given that a better proposal for a greater number of stakeholders is now on the table the directors, in their capacity as fiduciaries to the company, should halt cooperation with lenders on implementation of their plan.

“If the company is not able to make such a decision then this raises serious questions about the board’s decisions leading to this point, and about the position of the lenders, including major UK banks.”

Coltrane, which holds a 27% stake in Interserve has warned it will not vote for the latest rescue plan hammered out with lenders. This would leave shareholders with a mere 5% in the enlarged group after a debt for equity swap with major lenders.

Under Coltrane’s latest counter-proposal 55% of Interserve’s equity would be handed to lenders in exchange for £435m of the firm’s £630m debt.

Interserve would also raise £110m in a rights issue underwritten by Coltrane with shareholders retaining a 37% stake.

A statement from Interserve about the Coltrane move said:” A further announcement will be made in due course.  In the meantime, the board remains committed to achieving a consensual deleveraging plan.”

A showdown meeting to vote on lenders’ rescue deal is planned for 15 March.

In the event of failure to pass a plan lenders are reported to have placed Ernst & Young on alert to step in to manage the business if it was forced into administration.