Supermarkets are hoping for strong Christmas sales after growth slowed in the most recent trading period, new figures suggest.

Spending at the UK’s grocers grew by 1.5% in October, easing down from 1.9% in the previous period according to Nielsen.

This contrasted with strong growth of 3.1% in the same time period last year.

Meanwhile, rival Kantar Worldpanel showed growth of 2.6% in the 12 weeks to November 4, a slower rate than recent months.

It comes after the industry experienced a summer of bumper growth, boosted by barbecues and the World Cup.

But Christmas promotions could give grocers a much-needed seasonal boost, with festive spending on sparkling wines already up 8% in the week ending November 3, Nielsen said.

Mike Watkins, Nielsen’s UK head of retailer insight, said: “Both in-store promotions and media campaigns are more crucial than ever for the supermarkets this Christmas, to entice shoppers into their stores and ramp up consumer spending.

“With weaker than expected growth in October, the industry is under pressure to get shoppers into the habit of spending more over the next six weeks by showcasing what’s new and different in store.”

Kantar’s data showed that Tesco, Sainsbury’s and Morrisons all lost market share as Aldi and Lidl brought in an additional 14 million shopping trips compared with last year.

Asda was the only “big four” supermarket to maintain its share of shoppers, remaining at 15.3%, but its proposed merger partner Sainsbury’s dropped from 16.3% last year to 15.8%.

While Waitrose lost market share as its sales dropped by 1%, more middle class shoppers turned to Iceland.

The frozen food retailer recorded 5% sales growth and gained 0.1% of the market as it appealed to a wider demographic.

Fraser McKevitt, head of retail and consumer insight at Kantar, said this was being helped along by the chain’s Christmas advert, which was banned for its political content.

“Nearly 37% of Iceland’s sales come from the more affluent ABC1 social group – five years ago this was less than a third,” he said.

“Its banned palm oil Christmas advert is tugging at the heartstrings of Britain’s middle classes and could translate into strong sales growth, especially if it manages to pique the interest of the half of the population who haven’t shopped there in the past year.”