Bicycle on landing arrange to have them removed

It’ll be a condition of your
It’ll be a condition of your lease/tenancy that you do not obstruct the common parts of the building, so it’s no surprise that a notice such as this has been issued if you’re keeping bikes in this area. You are effectively in breach of your agreement and continuing to do so can ultimately result in you being evicted.

As has broadly been set out above, it’s irrelevant if you think you’re not doing any harm, access could be needed for all manner of reasons which are not apparent to you, not least in the event of emergency. There’s no particular obligation for the local authority to provide alternative bicycle parking either, although all new developments will generally be required to have some form of secure bicycle parking for residents under the planning regime.

Sorry to say it, but it’ll be a case of keeping the bikes in the flat from now on. This is said from many years experience of mine as a conveyancer, most recently with a major UK housebuilder. We find the problem is generally either with bikes or buggies, but there’s no alternative but to take enforcement action given the potential legal liability that will attach to the landlord as a consequence.

The first thing to do is to
The first thing to do is to read carefully the terms of your rental agreement (or lease if you are the leaseholder). They probably have and so you might as well know where you stand legally.
The second bit of advice I’d give is that in the short term you probably need to comply with their request (assuming that request is legal and you are breaking the T&Cs). That in NO WAY stops you fighting them! But if you knowingly continue to break whatever agreement you have with the property owners you will put yourself in a worse situation.
They’ll probably just come along and chop any locks you might have and if it is a private contractor involved they could add insult to injury by sending you the bill. Refuse to pay and you then go to court and so on. Don’t go there !
The next step would be to contact the council directly (or the housing association) and find out WHY the bikes need to be removed. The guys serving the notices are probably just private contractors and won’t give a s**t about you or your problems – they’re being paid to do a job and they’ll just do it even if they have to use an angle grinder. For which they’ll probably bill you! So talk to the council housing department. You could also try your local Citizens Advice Bureau.
FWIW my guess is that it’s fire Regs – or more strictly the fire risk assessment that the property owner will need to have carried out. And in that case I suspect you won’t get very far. But try and find out the why – only then will you be able to mount a counter-argument. It would also be worth nipping out with a camera and recording the current state of all the other stairwells. Are they are all perfectly clear ? Or are there lots of other people in the same position as yourself. Find out if they’ve been served similar notices. If after all that you still want help update the post with the situation. Although you might find posting on a CAB or tenants-rights forum just as fruitful (just pretend it’s pot plants – don’t mention you’re cyclists on a non-cycling forum 😉 ).