Department store group John Lewis expects its online sales to overtake store sales within four years as it ploughs £500m into IT systems.

An investment programme by John Lewis is expected to be completed by the end of 2018, which will include adding hundreds of staff to its IT department, the Mail on Sunday reported.

The forecast for web sales to overtake store sales is a year ahead of its original prediction.

Managing director Andy Street told the newspaper: “This has not blown our assumptions out of the water – but it has moved them forward.

“It’s very reassuring because it endorses everything we are doing.”

John Lewis’ investment will include completing state-of-the-art warehousing and investment into IT that will aid forward planning, analysis of shoppers’ buying habits. Street said it will give its customers a “seamless journey”.

Last month John Lewis reported its biggest-ever trading day on Black Friday, with sales primarily being drive through its website.