FACTORY export order books have weakened to their worst level since January 2013 amid political uncertainty at home and abroad, a report has warned.

The CBI said its survey of 488 manufacturers found output remained solid in the last quarter and should strengthen further in the coming three months.

However, firms saw total order books fall below normal levels between the August 20 and September 10 period, with the impact on exporters particularly severe.

Katya Hall, CBI deputy director general, said: "Against a backdrop of acute political uncertainty at home and abroad, exports orders for UK manufacturers are faltering, which is disappointing.

"However, it's encouraging output growth has remained solid and firms expect production to rise strongly in the next quarter."

The survey found 34 per cent of firms saw the volume of output rise in the last three months, while 19 per cent said it fell, giving a balance of plus 15 per cent.

It added 14 per cent of firms said their export order books were above normal and 38 per cent said they were below normal, giving a balance of minus 24 per cent.