The future of 76 businesses hangs in the balance after London's Olympic planners received powers to force them to sell their land.

The small businesses, which employ about 800 people, are yet to a agree prices for their plots on what is to become the 500-acre Olympic Park in Stratford, east London.

From Friday, they can be evicted under a compulsory purchase order (CPO) made by the industry secretary Alistair Darling.

The 76 firms, mostly in Marshgate Lane and Waterden Road, occupy the last 7% of the land that still needs to be acquired before the deadline of July next year. Building work on the 2012 Olympic venues is due to start early 2008.

In total, 211 companies had to vacate their premises. So far almost two thirds - including all the larger firms - have signed contracts to move, accounting for about 4,000 jobs and 93% of the land.

Of the 450 residents inside the Olympic Park, 250 have been relocated while another 200 still remain in Clayes Lane.

Two traveller communities - 15 families in Newham and 20 families in Hackney - also have to make way. The two boroughs are yet to grant planning permission for new traveller sites.

The London Development Agency (LDA), in charge of the buying, is spending £620 million on the land. That also includes building three new industrial parks - in Beckton, Leyton and Enfield, all further out of central London - where many of the 211 firms will be housed.

The CPO, made after a four-month public inquiry heard more than 100 objections, is the biggest since the slum clearances of the 1960s.

Nevertheless the LDA promised it would only use eviction as a last resort.

"Whilst we have been granted the CPO powers, we will continue to negotiate with landowners in an effort to reach agreements," said the LDA chief Manny Lewis.