The Frenchman currently lies just 94 points ahead of Reid at the top of the International Tennis Federation rankings.

Houdet finished third at the 2015 Masters and as a result has 64 points to defend.

His points from reaching the semi-finals of the Rio 2016 Paralympics will come into play if the 2011 winner fails to go beyond the round-robin group stage of this year’s event.

Rio Paralympic champion Reid, meanwhile, has no points from last year’s Masters to defend, but must reach the semi-finals this year if he is add anything to his ranking points total.

With the top two players from the two men’s round-robin groups of four players progressing to the semi-finals, there is a 50 point difference between finishing third and fourth and a 300 point difference between winning the event and finishing as runner-up.

"The one who will have the best result at the Masters between Gordon and I will be world number one at the end of the year," said Houdet.

"I have watched Novak [Djokovic] and Andy [Murray] at the ATP World Tour Finals fighting for this too and it was so nice.

"Right now I am feeling pretty good and quite relaxed, though nothing is guaranteed when you are competing at the highest level.

"If I go out and play strongly next week I’ve got a chance, but I know there are eight very strong world-class players in the mix so it will be very tough."

The ITF's season-ending Championship for the world's top singles players on the UNQLO Wheelchair Tennis Tour will be held until December 4.

The tournament will feature a round-robin stage initially and then subsequent knock-out matches and finals later in the tournament.

The event moved outside The Netherlands for the first time in 2011 and was held in Mechelen in Belgium in that year and 2012 before being held in Mission Viejo in California in 2013.

For the third successive year the prestigious tournament will be staged at Lee Valley Hockey and Tennis Centre at Queen Elizabeth Olympic Park in London, the venue for the London 2012 Paralympic wheelchair tennis event.

The top eight men's singles and women's singles players and the top six quad singles players at the ranking cut-off date of October 10 all qualified for the tournament.

Prior to the tournament starting, a host of competitors in the men's field pulled out.

Great Britain's Rio 2016 Paralympic silver medallist Alfie Hewett and compatriot Antony Cotterill will replace former three-time champion Shingo Kunieda and 2016 runner-up Lucas Sithole in the men's and quads competitions respectively with both players injured.

Former world number one Shraga Weinberg of Israel has also been added to the tournament as a replacement for current quads number one Dylan Alcott.

The Australian captured both the quad singles and quad doubles gold medals at the Rio Paralympics in September, but will not be competing due to injury.

The world’s current top three in the women’s singles rankings are all previous champions.

World number one and Rio Paralympic gold medallist Jiske Griffioen of The Netherlands will be in action.

She beat 2014 champion and her compatriot Aniek van Koot in last year's final to win her second Masters title in four years.

World number three Yui Kamiji of Japan will also be competing. 

She won the 2013 title to become the first non-Dutch winner of the women's singles.