Supermarkets are being given access to a government database to help prioritise food deliveries for elderly and vulnerable shoppers who have been ordered to stay at home under the government’s coronavirus crackdown.

With all the major grocers’ online delivery slots booked up weeks in advance, getting food to those self-isolating was top priority in a call between industry bosses and the environment secretary, George Eustice, on Tuesday.

Supermarket bosses discussed ways to ramp up deliveries and prioritise orders from those in need, including working on new ways to extend delivery networks such as teaming up with local taxi companies and takeaway delivery firms.

Sainsbury’s and Waitrose said they would begin writing to existing online customers, who were also on the government database, to offer them a delivery slot. Sainsbury’s said it expected to begin contacting people next week and was also working on ways to secure details for vulnerable people living in Wales, Scotland and Northern Ireland.

Sainsbury’s has already used information from its Nectar loyalty scheme to try to prioritise elderly shoppers online, proactively contacting 270,000 people. It also has a helpline which vulnerable shoppers can ring for help in booking delivery slots. However, shoppers told the Guardian that accessing the helpline was difficult because of very high demand.

Sainsbury’s admitted that its customer careline had been inundated with requests from elderly and vulnerable customers, with one year’s worth of contacts in two weeks.

It said it had already booked delivery slots for 115,000 elderly, disabled and vulnerable customers this week.

The retailer is also closing about 10 smaller local stores, mostly in locations such as train stations, to prioritise busier outlets and online.

While many supermarkets have set aside special shopping periods in store for the vulnerable and elderly, the latest advice to stay at home has stepped up the need for delivery services.

The government is also teaming up with food service providers Brakes and Bidfood to put together an emergency food parcel scheme that could provide essentials to 300,000 of the most vulnerable of 1.5 million people identified as needing assistance by the government.

The scheme, which could launch as early as next week, is expected to link up the delivery networks of the food service companies – which usually supply catering businesses and restaurants – with local volunteers and charities.

One industry source said that the government had initially approached supermarkets to support the scheme but it had quickly become apparent that food service firms had more capacity to cope because of lost orders from their usual clients, most of which have been forced to close under the government’s measures to control the spread of the virus.

Morrisons said it had already delivered 10,000 boxes of essential groceries after beginning tests on a new scheme this week which operates using couriers rather than via its Morrisons.com network. The retailer expects to ramp up production of two £30 boxes of essentials in the coming week.

Morrisons is also extending its Morrisons.com and quick delivery service via Amazon’s Prime Now subscription option by taking on thousands of staff to pick, pack and deliver groceries from 100 more stores in the coming month.

Marks & Spencer is launching a service with takeaway courier firm Deliveroo in which it will deliver bread, milk and other essentials from franchise outlets on BP forecourts.

Tesco is bringing in 8,000 new drivers to help with deliveries and said it had already appointed 12,500 new staff out of a total of 20,000 required.

Tesco said it would be joining other supermarkets by installing protective screens for staff, marking out safe distances for queueing and creating separate entrances and exits for shoppers.

New rules announced on Monday night stipulate that retailers remaining open during the high street lockdown, such as supermarkets, must ensure there is a 2-metre distance between customers and staff and that shoppers enter in small groups, so that spaces do not become crowded. The government has also ordered retailers to manage queues outside their stores.