WILDCAT strikes at Coryton oil refinery have escalated after bosses threatened protesters with the sack.

Between 400 and 500 workers joined a mass picket outside the Petroplus-owned oil refinery, yesterday.

Several strikers claimed they were defying letters from their bosses, threatening the sack, if they walked out again.

Some 40 workers from Tilbury power station also walked out in sympathy. This came after about 150 workers struck on Monday, in protest at the employment of foreign workers at the Lindsey Oil Refinery, in Lincolnshire.

FULL REPORT IN WEDNESDAY'S ECHO