Jurors in the year-long fertiliser bomb plot trial at the Old Bailey were today given a majority direction by the judge in the case.

Sir Michael Astill told the jury he would accept verdicts on which at least 10 of their number were agreed.

The jury had earlier retired for a 21st day of deliberations.

Seven British men were arrested in March 2004 following the discovery of more than half a ton of chemical fertiliser in storage in west London.

The prosecution alleges they were involved in a plot to bomb targets in Britain, including the Bluewater shopping centre in Kent and the Ministry of Sound nightclub in London, and to hit gas and electricity supplies.

The defendants deny there was a plot. Some say they did not know what the fertiliser was, that they were only interested in sending money and supplies to fighters in Kashmir and Afghanistan, or that they were duped.

Omar Khyam, 25, his brother Shujah Mahmood, 20, Waheed Mahmood, 35, and Jawad Akbar, 23, all from Crawley, West Sussex; Anthony Garcia, 25, of Barkingside, east London; Nabeel Hussain, 22, of Horley, Surrey; and Salahuddin Amin, 32, of Luton, Bedfordshire, deny conspiring to cause explosions likely to endanger life between January 1 2003 and March 31 2004.

Khyam, Garcia and Hussain also deny a charge under the Terrorism Act of possessing 1,300lb (600kg) of ammonium nitrate fertiliser for terrorism.

Khyam and Shujah Mahmood further deny possessing aluminium powder for terrorism.