Michael Gilbert 
Trouble [PDF ebook] 

Explosives, destined for a terrorist bombing campaign, are being smuggled into the UK via the Channel coast. One plot is foiled but the security services suspect another. A seemingly unconnected problem occurs when there are race riots in London. However, the overstretched authorities, ranging from the magistracy to the Prime Minister throw everything they have at the two problems, which soon appear to be connected in some way. The true extent of the nightmare facing the government and the solution depends on a single, quite astonishing, piece of evidence.