Cancer Research UK is the world's leading charity dedicated to beating cancer through research. Millions of lives have been saved by discovering new ways to prevent, diagnose and treat cancer, and survival has doubled over the past 40 years.

Every day in the UK there are more than 400 people diagnosed with cancer who will survive the disease for more than 10 years thanks to research.

CRUK fund research into more than 200 types of cancer, including the one that's most important to you. From the most common - such as breast, bowel, lung and prostate cancers - to rare types of tumour and children's cancers, they support groundbreaking science that benefits everyone.

I'm a double cancer survivor, long distance walker and cyclist who does various challenges for different charities, mainly cancer-related. Amongst other things I've cycled from Lands End to John o'Groats (2003), from Rotterdam to Lemvig in Denmark (2005), completed the ascent of all 214 'Wainwrights' in the Lake District in only 55 days (2009), cycled 4,500 miles around the coast of Great Britain (2011), cycled all 42 of the accessible Western Isles of Scotland in under a month (2012) and twice abseiled 230 ft from the top of The Big One in Blackpool. Altogether I've raised over £60,000 for my charities including The Christie, Cancer Research UK and the Rosemere Cancer Foundation, and I was mightily chuffed to receive the British Empire Medal in the 2014 New Year's Honours List. My latest challenge is to climb 542 separate hills, fells and mountains in the Lake District during 2016, to raise funds for Cancer Research UK, who do an enormous amount to improve the outcomes for all cancer patients.

My Wainwrights challenge was quite a milestone - climbing all 214 of AW's fells in only 55 days and raising over £10,000 in the process. Since then I've done a few challenges involving cycling and other things, but I kept wondering whether there was some other way that I could push myself on foot.

Then recently I found myself reading through Bill Birkett's book - the Complete Lakeland Fells - which had been on my bookshelf for ages, and a train of thought set off... 541 fells, hills and mountains in the English Lake District - more than twice the number that Wainwright described, and all over 1,000 ft high. Could I set myself the target of climbing all of them in one year?

I toyed with the idea but also wondered how to make the most of the opportunity to raise as much money as possible for Cancer Research UK.  On New Year's Eve, 2015, I hit upon the idea - climb all 541 'Birketts' in 2016 (plus Castle Crag in Borrowdale, the only 'Wainwright' that fails to qualify as a Birkett by being under 1,000 ft).

542 fells in all. But the main difference will be in the fund-raising. Instead of asking for a one-off donation from family, friends and friends of friends, I would ask all supporters - as many as humanly possible - to set aside 10p for every completed 'top' until the challenge is complete. No-one is likely to be asked for more than £1 a day, or £3 - £4 per week, but at the end of the challenge everyone should have set aside £54.20. This way, 500 donors would contribute over £25,000. And if we could get 1,000, or more... (well, we have to aim high).

So that's the idea:

* NO donations upfront

* I HAVE to perform!
* TELL me if you're 'IN' by leaving a comment on this blog (they're all moderated and I'll see your email address to contact you back - or find me on Facebook (I'm easy to find, just search Bill Honeywell or '542 in 2016') and leave a post or message.

* Find a bottle or a jar to start collecting contributions

* SIGN UP to this blog to keep up with progress (be prepared to get lots of blogs - there's 542 hills to climb!
* SHARE this with all your friends and colleagues, especially those on Facebook and Twitter, keep sharing and ask your friends to do the same.

Together we WILL beat cancer.