Ocado has warned of product shortages as supply chains are hit by the impact of the coronavirus pandemic.

The online grocer has informed customers via email that they may see “an increase of missing items and substitutions over the next few weeks”.

As cases of Covid-19 continue to rise across the UK, Ocado’s suppliers have cut product choices to mitigate against the effects of staff sickness and self-isolation on output.

Food producers are struggling to deal with staffing problems, hospitality clients that have been forced to close and delays at the EU borders.

Ocado said while customers may not get their first choice, there is still plenty of food available.

The retailer, along with other grocers including Tesco and Sainsbury’s, saw a rush of online orders last week after the government announced a third national lockdown.

An Ocado spokesperson said: “Staff absences across the supply chain may lead to an increase in product substitutions for a small number of customers as some suppliers consolidate their offering to maintain output.”

The email to customers said: “Changes to the UK supply chain have affected some of our suppliers and may result in an increase of missing items and substitutions over the next few weeks.

“We apologise for any inconvenience caused and we are working hard to mitigate any impact.”