East London has become the unlikely nerve centre of a battle between delivery services to get groceries to your front door on the same day.

Bromley-by-Bow is home to Amazon Fresh, which launched its trial in June , and is the centre of operations for Sainsbury’s, which has just announced it will step up its online offering to compete.

The company will be recruiting the first of 470 people for its so-called “dark store” in east London, servicing three pilot areas.

The 185,000 sq ft “ Online Fulfilment Centre ”, in the former Royal Mail building, is due to open this autumn handling 25,000 orders a week and is expected to grow to employ 900 people by 2020.

Neither Amazon Fresh , a subscription service, nor Sainsbury’s will cover the whole of east London in its early stages, although Amazon does deliver to key centres such as Canary Wharf.

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Meanwhile Sainsbury’s has accelerated its online operation to be ready for a wider service by Christmas, by which time it could have taken over Home Retail Group, owner of Argos, part of a strategy to become a key online player.

Sainsbury's "dark store" sits just to the south of Amazon Fresh on the River Lea

Sainsbury’s director of online Robbie Feather said: “As our online sales grow, we are seeing an increasing proportion of orders placed for next-day delivery, so this trial is a natural next step in delivering our strategy to help customers shop whenever and wherever they want.”

The supermarket giant said online grocery sales rose by more than 8% in the three months to June.

Tesco, which already runs same-day click and collect groceries at 200 of its stores, is also trialling same-day delivery operating out of six dark stores.

Consumer test

Consumer service Which? recently completed a test of Amazon Fresh and concluded: “If you’re a Prime member, Fresh is certainly worth sampling. But the monthly fee means it’s probably only worth it for those who are happy to order regularly.”

Amazon Fresh costs £6.99 a month on top of the £79 a year Prime subscription.