A NORTH-South divide in mail delivery fell in favour of Sunderland on a day that Royal Mail bosses admitted their service was "not good enough".

The postal delivery service admitted that more than a million first class letters fail to arrive on time every day.

Despite this, Sunderland was heralded as the best performing postcode area for next-day delivery while the worst was south-west London.

Performance figures for the period from April last year to March showed Royal Mail had not met 80 per cent of its delivery targets.

Adam Crozier, group chief executive, said: "We are improving and we are getting better. However, it is absolutely not good enough.

"We have a number of plans in place to solve this. It is very important for our business and social customers that we do and I am confident that we can and will improve."

As well as failing to meet the minimum performance targets for the delivery of first and second class post, Royal Mail also missed targets for its heavily advertised special delivery service.