Why is Christmas dinner more expensive this year?

The cost of Christmas dinner is set to increase, with even the UK's cheapest supermarket spread destined to be 16% more expensive than in 2016.

That's according to Good Housekeeping magazine's annual festive food survey which looked at Britain's 10 biggest stores.

A Christmas meal for eight people - including 11 essential components, bought at the lowest price available - has risen from £19.82 last year to £23.53 this festive season.

Around the table, this equates to £2.94 per head compared with £2.48 last year.

It's worth noting though, of course, that what you end up paying for Christmas dinner will depend on how you shop and how much time you have to do it, as BBC Reality Check discovered previously.

Good Housekeeping also have very specific criteria for the ingredients they choose.

Nine of the 11 items are more expensive in their cheapest form, including turkey. The cheapest bird, according to Good Housekeeping is now up to £8.99 from £8 - a 12% increase.

Potatoes have seen the biggest jump from 29p for the cheapest bag last year to £1.49 for a comparable amount this time.

Good Housekeeping says it will only accept Maris Piper or King Edward potatoes in its survey and a 1.5kg bag of Maris Piper potatoes from Co-op costing £1.49 is the cheapest price submitted by any retailer that fits its requirements.

However, the Agriculture and Horticulture Development Board says growers are being paid less for their potatoes this year and the consumer is also paying less - and indeed, a quick comparison site check suggests you can buy 2.5kg of potatoes from many stores for significantly less than £1.49.

So, it's all about the type of spuds, it seems.

When it comes to dessert, Christmas pudding fans, at least, will be pleased to see a drop in price, but other sweet treats have gone up.

The cheapest pack of six mince pies is 9p more this year, brandy butter is 24p more and it seems you can't get a Christmas cake for less than £3.99 compared with £3 in 2016.

Overall, nine supermarkets are more expensive than last year, with Aldi, Morrisons and Iceland all increasing their prices by more than 13%.

Marks & Spencer is the only supermarket whose basket has got cheaper, dropping its prices by more than 20%.

Lidl offers the most cost-effective overall deal for Christmas dinner at £25.53, whilst Waitrose is deemed most expensive at £41.47.

The findings from Good Housekeeping represent the biggest year-on-year cost increase since it began its survey nine years ago.

This reflects rising food prices across the UK, as the weak pound pushes up import costs.

Food inflation hit a three-year high in May, according to the British Retail Consortium, and is now nearing 4.2% - the highest since October 2013.

Much of this is down to the "sterling effect" - the sharp fall in the value of the pound following the EU referendum.

'Volatility'

Brexit-induced uncertainty has affected supermarkets, with Sainsbury's, for one, warning about rising costs and falling consumer confidence as it reported a drop in annual profits.

The instability has also hit farmers, unsure how to price their goods in the current climate.

A National Farmers Union spokesman told the BBC: "British farmers have been dealing with a lot of uncertainty and price volatility since the vote to leave the EU.

"But as producers of the raw ingredients for a food and drink sector, farmers are price-takers rather than price-makers; increasing costs on farm, for example, are rarely passed on to the companies buying the farmers' produce."

Steve Dresser, director at Grocery Insight, said the problems are similar for supermarkets from a business perspective: "The diminished pound means that any supplies bought in Europe are more expensive than they were pre-Brexit when Sterling was stronger.

"Lots of supply agreements are done with a long outlook, which means that deals may have been struck for Christmas well before the result of the referendum was known.

"Therefore, these supply agreements will reflect the changes in the market and lead to higher prices, despite the retailers best efforts to keep a lid on increases.

Supermarket choice 'crucial'

But festive cheer need not disappear right away. Shoppers can still save by shopping around.

"Bargains are thin on the ground this Christmas, so supermarket choice is crucial," said Caroline Bloor, consumer director at Good Housekeeping.

"A turkey will usually be your biggest outlay, so if you can find quality and value, you'll be off to a great start. Aldi and Lidl have the cheapest one this year. Now is not the time for loyalty - swapping supermarkets is the best way to save."

Vicki Parry, 27, from Heswall in Merseyside, cooks Christmas lunch every year for her parents and three siblings, as well as her own two young children.

She says the family found that researching the best deal can make a big difference.

"Last year we really noticed the price increase - food, as with everything else, seems to be getting more expensive.

"Our solution as a family was to shop around online and in-store. We knew what we wanted, but rather than buy all our ingredients from one place, we tried to mix things up.

"Taking the time definitely saved us money - we'll do the same this year."