Graham Kibble-White tries to get to the bottom of Doctor Who's accent...
On Christmas Day 1965, the Doctor took time out from an epic battle with the Daleks to partake in an odd 25-minute run-around which saw him in a silent film-style encounter with the likes of Charlie Chaplin and the Keystone Kops.
As if that wasn't bizarre enough, at the end of the episode the Timelord - then in his first incarnation, played by William Hartnell - caused many a viewer to choke on their turkey by suddenly turning straight to camera and addressing the TV audience across the land. "Incidentally," he chuckled, "a happy Christmas to all of you at home."
Although it was all meant in a spirit of fun, the audience of the day wasn't impressed.
"It was one of the worst programmes I have seen and definitely not Christmas material," wrote one contemporary viewer. Even now, hardcore Who fans still wince at the memory.
Four decades on, and for only the second time in the programme's long history, the Tardis is once again materialising onto our TV screens on Christmas Day. But this time around it's all very different.
Rather than an Edwardian gentleman with dodgy dentistry at the helm, the new Doctor, David Tennant, is all Carnaby Street swagger and perfect teeth.
Gone too, is the whimsical seasonal run-around. Instead, The Christmas Invasion brings us an Independence Day-scale adventure of alien invasion and impending Armageddon, all wrapped up in Christmas tinsel, as trumpet-playing Santas and evil spinning fir trees wreak havoc across London.
As you can probably tell, the episode isn't without a sense of humour, with the Doctor at one point breaking off from making a moving speech to the evil alien Sycorax about the sanctity of life to declare, "Oh. Sorry, that was The Lion King".
Plus he ends up saving the day with that humble Christmas stocking filler, the satsuma.
It all makes for perfect seasonal viewing, which has unapologetically been scheduled as the jewel in the BBC's festive crown this year, charged with seeing off the threat posed by Chris Tarrant and Who Wants To Be A Millionaire? Celebrity on ITV1.
For fans everywhere, it will also provide them with their first chance to properly size up the new man in the Tardis, having only enjoyed a brief sample of David's take on the role in a Children In Need special last month.
One matter which has been open to conjecture ever since the 34-year-old actor won the part has been what accent he would use in the role.
Born in Bathgate, West Lothian, Scotland, fans wondered if he would follow the example of seventh Doctor, Sylvester McCoy (who played the part from 1986 to 1989 on screen) and speak in his native Scottish brogue.
However, this incarnation of the time-traveller from Gallifrey has opted to adopt a 'mockney' dialect, announcing "'Appy Christmas" as he steps out of the Tardis for the first time.
Sadly, the reason for the dropped h's may now be lost in the web of time. The series' lead writer and executive producer, Russell T Davies, admitted there was originally a line in the script where Mickey (played by Noel Clarke) commented that the new Doctor had somehow taken on the accent of his companion Rose (Billie Piper). But alas, due to timing reasons, it was cut.
"We've kept saying the accent issue would be resolved in the Christmas special," laughs David, "but now that's no longer the case."
However, a preview of the delights the show has in store next year does reveal that for at least one story, he will be allowed to lapse into his native tongue when the Tardis takes him to Scotland in Victorian times.
When he took on the role earlier in the year, David was thrilled to receive two letters of congratulation.
"I did get a couple of very nice notes, yes," he reveals. "One was from where they were shooting Monarch Of The Glen, from Tom Baker (who played the part from 1974-1981) and the other from Distant Shores and Peter Davison (1982-1984). I was very honoured."
Since then, the latter has actually paid a visit to the set, his children being huge fans of the show, although, as David jokes, "They probably don't realise their dad was ever in it."
One former Doctor who hasn't been in touch just yet is Christopher Eccleston, who sensationally quit the series in March after just one episode of the new series had been broadcast.
"I didn't get to speak to him," says David, "because the regeneration sequences (when one Doctor transforms into another) were shot on separate days due to technical reasons."
Despite being a life-long fan of the programme, he is determined to make the character - now in its tenth incarnation - his own.
"I haven't drawn on any of the earlier Doctors' portrayal, not particularly consciously. I suppose having that knowledge of the show might influence me, though.
"I am aware there's always the danger of playing it too quirkily."
He's obviously still smitten with the role. "It is like no other job in the world, you are sword-fighting one day, swinging off ledges on another. It never fails to surprise and delight.
"We literally have about one 'wow!' moment a week," he smiles. "Standing in the arena of the Sycorax spaceship was an early one."
Eclipsing even that thrill is one we won't get to see on our screens until next year, when the Doctor comes face-to-face with former companion Sarah Jane Smith, who accompanied both Jon Pertwee and Tom Baker on their time travels in the 1970s.
Still played by Elisabeth Sladen, David admits it was a great thrill to work with one of his childhood heroes.
"She was calling me Doctor, which seemed really weird," he laughs.
Get used to it, Mr Tennant, because after Christmas, so will the rest of us.
As the Doctor says, at the climax of The Christmas Invasion, still clad in a fetching pair of pin-stripe nightwear following a post-regenerative period of bed rest, "Not bad for a bloke in jim-jams". ..SUPL: