Ed Miliband has demanded an urgent investigation after Prax Group, which owns one of the last remaining oil refineries in the UK, as well as petrol stations and North Sea assets, collapsed.
State Oil, the parent company of Prax, which owns around 200 petrol stations and has interests in Shetland oilfields, has called in administrators.
The move, reported last night by Sky News, comes amid in creasing losses at the Prax Lindsey Refinery in Lincolnshire.
The refinery employs around 440 people and is one of just five large oil refineries remaining in the UK.
Now, the energy secretary has written to the Insolvency Service to order an inquiry into the collapse of the refinery amid concerns over its management, The Times reports.
The Insolvency Service secured court approval to take over management of the Prax refinery after issuing a winding-up order against the company on Monday.
Michael Shanks, the junior energy minister, said the company's workers had been "badly let down".
FTSE 100
The UK's flagship share index, the FTSE 100, was down 36 points at 8,776 shortly after opening this morning.
Brent crude oil futures were up 0.27% at $66.74 a barrel.