Young Lions fan and schoolmates from Surrey Square take the fight for Vimizim to Downing Street
Harvey, 6, is one of 78 youngsters in the UK with Morquio, which is an ultra-rare inherited disease and means that children like Harvey rarely grow above three foot tall or live beyond their twenties.
A successful clinical trial of Vimizim has shown that the drug can help children like Harvey grow stronger, need fewer operations, walk without mobility aids and live for longer.
Harvey's parents, Mum Vikki and Dad Dean, have campaigned tirelessly in a bid to ask NHS England to fund Vimizim to help not just Harvey, but all other children with Morquio.
On Friday schoolmates of Harvey hit the campaign trail too.
An early start saw Millwall's blue routemaster bus leave The Den with Zampa and Bolina, picking up Harvey, his family and school friends en route, bringing the Old Kent Road to a temporary standstill as cars slowed down and beeped their horns in support.
The magic of the blue bus rubbed off on the children, who chatted away happily on the top deck as it sailed through the Elephant & Castle, past St Thomas' Hospital and over Westminster Bridge before turning into Whitehall.
Following rigorous security checks, the official party were let through the big security gates as the youngsters personally delivered their own special hand written letters to the Prime Minister, which were accepted on his behalf by an aide.
After posing for photos on the doorstep of No.10, the excitement levels were cranked up a notch as driver John West decided to add a little detour via Trafalgar Square, The Mall, Buckingham Palace and Constitution Hill.
Zampa and Bolina spent much of the journey waving to tourists, members of the public and giving thumbs up to drivers, all of whom who were amused, bemused and delighted in equal measure at the unexpected sight of our favourite furry friends.
Once back south of the river, Harvey, his family and the rest of the party disembarked on the Old Kent Road once again, letters delivered to Downing Street and point very much made.
A decision on the possible funding of Vimizim by NHS England is expected to be made in the second week of December. You can still write to your local MP c/o Houses of Parliament and sign Harvey's petition here