Work has started on the final link of the Channel Tunnel high speed railway from London to mainland Europe.

A giant boring machine, itself the length of a football field, will tunnel nearly 7.5 kilometres (almost five miles) from Stratford in east London to St Pancras railway station in the heart of the capital.

Progressing at a rate of 95 metres a week, the boring machine, nicknamed Annie, will shift 792,000 tons of earth – the equivalent weight of 88,000 double decker buses.