Morrisons has reported sales growth in the first quarter despite “highly volatile” trading patterns and a worse-than-expected Easter due to the ongoing coronavirus lockdown.

For the 14-week period to May 10, the supermarket said like-for-like sales excluding fuel were up 5.7% – with retail sales up 5.1% and wholesale 0.6%.

The retailer said that retail like-for-like sales were up 5% for the first six weeks of the year, with weeks five to seven marked by “considerable stocking up” by customers, which pulled sales forward.

However, Morrisons said this had been offset somewhat by Easter being affected by the lockdown, with sales “significantly down year on year” meaning a negative retail sales contribution like for like in weeks eight to 11 of the period.

The supermarket said that in recent weeks normal trading hours have resumed and it has been able to install protective screens to enable all checkouts to open safely.

It also noted that customers have become more “accustomed to the social distancing protocol in stores and are spreading shopping trips throughout the week”.

As a result it said retail like-for-like sales were up 9.6% between weeks 12 and 14 of the period.

Morrisons also said its online operations are “expanding significantly and at pace” during the ongoing lockdown.

The retailer said it had more than doubled the number of weekly home-delivery slots since the lockdown began, through a substantial increase in the number of store-pick stores through its partnership with Ocado.

It has also rolled out click-and-collect and hopes to have it available in 280 stores by mid June. The retailer said it has also “significantly expanded the Morrisons store on Amazon Prime Now”.

While the supermarket chain said it remained in a robust financial position at the end of the first quarter, it noted that as it continued to respond to the crisis it had adopted an interim core purpose: “To play our full part in feeding the nation – it’s more than our job.”

Chief executive David Potts said: “We are facing into the unprecedented current challenges and are playing our full part to help feed the nation: working with determination, creativity and pace to serve customers as well as we possibly can.

“The professionalism, enthusiasm and resourcefulness of our frontline key worker colleagues is extraordinary and is showing Morrisons at its very best.

“I’d like to thank every single colleague: you are Morrisons’ most important and most valued assets and are making a vital difference to so many people and communities across Britain.”