Three hundred workers at a Welsh oil refinery were braced yesterday for Christmas on the dole after a notorious "asset stripper" wrecked a buyout at the last moment.

A four-year government-backed bid to sell the Murco-run Milford Haven site was dashed when the Swiss-based Klesch Group pulled out - five days after the final deadline.

In a message to staff, owner Murphy immediately put them on notice that the "disappointing" development will "result in a significant number of redundancies."

Just one hundred of the refinery's 400 workers are expected to be kept on when the operation is scaled down to oil storage.

Unite Wales secretary Andy Richards said: "Milford Haven is a crucial asset to the Welsh economy and its permanent closure would not only be a huge blow for jobs in Wales, but potentially undermine the security of future fuel supplies for the UK."

Murco, the Welsh government and Wales Secretary Stephen Crabb were united in their criticism of Klesch for backing out of the deal.

And Labour MP Tom Greatrex said yesterday that the "asset stripping" company should be stopped from snapping up British steelworks from Tata.

The Scottish MP warned MPs that Klesch has a number of Tata steel factories across Britain in its sights and has already set out job cut plans.

He told the Prime Minister that "people across the UK will judge the Klesch group by their actions" and called on him to prevent the purchase.

David Cameron said the collapse of the Milford Haven buyout was "disappointing" but insisted Klesch were buying the steelworks as a "going concern."