A music teacher who has been given less than a year to live hopes to cross the finish line at the London Marathon one last time next Sunday. Nathaniel Dye, 38, has stage four bowel cancer which has spread throughout his body, including to his brain, lungs and liver.

The assisted dying campaigner said his latest challenge is yet more evidence that terminally ill people like him are “anything but suicidal” and simply want control over their deaths when they reach a point of no return. He added: “No one can accuse me of wanting to give up on life.”

Nathaniel was offered a place in this year’s race after being honoured with a Spirit of the London Marathon Award for his efforts last year. He completed the 26.2 mile course in five hours and 49 minutes — while playing the trombone.

Nathaniel said: “I genuinely don’t know what’s going to happen on race day. I’ve lost a lot of fitness, gained a lot of weight and I’ve got at least 50 tumours in me somewhere.

“So I’m leaving the trombone at home. I’ve got nothing to prove but it’s more likely than not that I won’t be breathing, let alone running, next year, so I may as well go for it.”

Scans recently revealed that his prognosis had worsened after he began experiencing back pain while on a break from treatments. He is now undergoing gruelling chemotherapy, along with taking steroids and morphine.

Nathaniel added: “Obviously no one has given up, there are some chemo options. But it’s a balance of probability thing. The tumours are growing more quickly, therefore it’s likely to kill me sooner.”

The keen runner has completed dozens of marathons, including while training for ultramarathons.

However, the toll of his disease means his only goal this year is to reach the finish line within the eight-hour time limit. He will be joined for the challenge by his brother Jon, 45.

Nathaniel, of east London, is a passionate campaigner who was awarded an MBE last year for his efforts to raise awareness of cancer.

He also campaigns for a change in the law on assisted dying, regularly attending rallies and events in Westminster. The Express backs such reform through the Give Us Our Last Rights crusade.

The Terminally Ill Adults (End of Life) Bill introduced by Labour MP Kim Leadbeater is due to return to the Commons for debate on May 16.

Nathaniel, who has followed its progress closely, said November’s debate showed “Parliament at its best”. But he fears that those who oppose the bill for ideological reasons, such as religious beliefs, “appear increasingly desperate”.

“There’s a vocal anti lobby," he added. "I’m concerned that, for example, there are certain voices who appear to be pitting disabled people against each other.

“I’m disabled and I feel safe with this bill, because I’m looking at the exact potential law which specifically excludes disabled people who are not terminally ill.”

Noting intensifying attacks on the process of drafting the legislation, and claims that it is being rushed through, he said: “It’s tactics like that that are worrying me.

"It strikes me that when the argument is lost, all that’s left to attack is the procedure.” Nathaniel added: “This is about shortening death, not shortening life, as Kim Leadbeater has said right from the start.

“No one can accuse me of wanting to give up on life. If I was seriously looking into Dignitas, now would be the time [to go] whilst certain I'm able to travel alone. This is ridiculous. I have plenty of living left to do — I'm running a marathon in seven days."

Nathaniel has raised almost £40,000 for Macmillan Cancer Support in recent years. You can make a donation and help him reach the milestone here.