Ocado has recorded an increasing number of late deliveries as its Hatfield operation struggles with capacity problems.

The online grocer has been struggling to keep up with demand in recent months, with the proportion of deliveries it makes either on time or early varying between 90% and 95%, down from 95.5% for the three months to August 7, according to The Daily Telegraph.

Ocado claimed it has rarely slipped below 90% this year and its grocery rivals only make around 80% of deliveries on time or early.

The online grocer is building a new distribution centre in Warwickshire, due to open in 2013, to ease pressure on its Hatfield operation which Ocado has admitted has had capacity problems.

Founder and chief executive Tim Steiner admitted earleir this year that the business is suffering from “growing pains”. In September, Ocado warned that full year profit margins are likely to fall.