Amazon has introduced a sales event called Prime Day in an attempt to encourage customers to sign up for its Prime membership.

The event on 15 July claims to have more deals than Black Friday and will be exclusive to Amazon Prime members.

The e-tail giant is hosting the event on the eve of its 20th birthday and will be available to Prime members in the UK, US, Spain, Japan, Italy, Germany, France, Canada and Austria.

In order to encourage customers to sign up for its Prime membership Amazon is offering a £20 discount for those who join before 8 July. At a cost of £59 per year (normally £79), customers can choose from options including one-hour delivery within London, unlimited streaming of movies and TV episodes, unlimited cloud photo storage, and access to 800,000 Kindle books to borrow.

Greg Greeley, vice president Amazon Prime, said: "Prime Day is a one-day only event filled with more deals than Black Friday, exclusively for Prime members around the globe.

"Members tell us every day how much they love Prime and we will keep making it better. If you're not already a Prime member, you'll want to join so you don’t miss out on one of the biggest deals extravaganzas in the world."

Last week, Amazon announced its plans to bring its one-hour Prime delivery service to Londoners.

The Prime Now service will be available for over 10,000 items in selected London postcodes, with plans to cover the rest of the capital and other UK cities later this year. This is the first time the service has been available outside the US, after the online retail giant launched the one-hour service in New York at the end of 2014.

The service can be accessed through the Prime Now mobile app, and customers with a Prime account can choose the one-hour delivery option seven days a week for the additional price of £6.99. Customers willing to wait two hours, or same-day delivery can choose free delivery.