Leon has followed Pret’s lead with an ‘unlimited’ coffee offer of £15 for 30 days, which aims to get office workers back into the city.

The offer, which is actually limited to 75 coffees across the period according to the terms and conditions, is redeemable via a unique code.

It can only be used via purchases on smart order, Leon’s click and collect service, not at kiosks or tills.

Leon said the offer was for “as many coffees as you can drink - or carry”.

Announcing the offer on Twitter “You read it right. We’re offering you 30 days of unlimited coffee for £15.

“All you’ve got to do is follow the link and buy it tonight to make tomorrow’s morning commute just a little bit brighter.”

Pret’s coffee subscription service offers customers up to five drinks per day – including all coffee products, teas, hot chocolates, smoothies and frappes - for a fixed monthly price of £20.

The service is accessible via email, phone or digital wallet, with one per transaction up to five times a day, and the first month free of charge.