It’s Christmas Day and many of us are doing what we usually do on the biggest festive day in the Western calendar when most shops are shut – shopping. Yep, Britons are expected to spend over £700m online today.

OK, that’s relatively small-scale compared to Black Friday’s spend (£1bn-plus) but it’s still pretty huge considering it’s a figure that’s gone from zero not so many years ago.

To be precise, Experian and IMRG think we’ll spend £728m before midnight, buoyed by clearance sales that have started early and – presumably – aided by all those gift cards we found in our Christmas stockings.

We’ll be doing a lot of the shopping on our brand new iPhones, Galaxy Edges, Kindle Fires, iPads, Microsoft Surfaces and Macbooks too, because electricals proved pretty popular as gift (or self-gift) ideas in the last few weeks.

So, that £728m. It’s 11% up on last year and will be followed by a 22% surge tomorrow with Boxing Day online spend set to reach £856m.

While our Christmas Day online shopping ‘trip’ is part leisure activity, it’s largely about bargains. Historically high discounts will be key, especially at fashion retailers after the AW15 season turned into a nightmare on the back of the wrong weather and other problems.

And it’s been a nightmare in multiple markets.

• Official figures show French consumer spending has been weak too. It fell unexpectedly by 1.1% in November compared to the month before, which may not sound like much but clothing spend fell 4.7% as the weather stayed warm. And let’s never forget the impact of the November terrorist attacks that affected shopper sentiment too. Both those factors are likely to have continued to influence shopper behaviour during December.
• The US has also seen unseasonably warm weather in parts of the country usually expected to be cold, as well as headline-grabbing weather that has tragically left 14 people dead. The former issue has hit sales of fashion product hard and the latter will have people focusing on far more important things than shopping. And NRF survey released on December 15 showed that 90% of shoppers still had significant amounts of holiday shopping to do, which means they’d have been able to take advantage of discounts. As many as 22% of survey respondents said they wait until the last minute in order to get the best deals.

Back with the UK, there are deals a-plenty. Big discounts were already available this week with chains starting their clearance sales early and the usual 30%-off replaced by 50, 60 or 70%-off. Even the luxury sector is offering 50%-off.

It’s interesting that a Barclaycard study showed that 26% of people who planned to shop in this season’s clearance sales did so on Wednesday – that’s two days before Christmas when shops should still be confidently selling their products at full price.

Retail analyst Richard Hyman said over 70% of the UK high street was already in clearance mode, something that hadn’t been seen in his 30 years in the business. And accountancy firm Deloitte said the size of the discounts themselves were the biggest since 2008 – that was the year when the world was in the middle of a devastating downturn rather than the upturn that we’re supposed to be seeing in 2015.

The Boxing Day online spend will be added to by a massive spend in-store as everyone heads to the malls on Saturday with figures from VoucherCodes and the Centre for Retail Research suggesting 22m of us will spend £3.74bn in total on Saturday alone, up 6% on last year.

What this means for retailers is that much of their unsold stock will be shifted. But so much of it will be sold at a discount that margins will be under pressure. We’ll have to wait a few more weeks until we find out how much they’ve been under pressure.