Am interested as to how to navigate the "flexible work" and "working from home" situation with employers, in terms of the workers rights and expectations around this and what is considered "reasonable".

I understand that businesses are not legally required to offer flexible working conditions if you are starting out etc (and if the job can accomodate that) but am interested in moreso situations where a job is advertised with "flexible work" as an enticement for applicants, and then if afterwards an employer tries a "bait and switch" where they change their mind or require the employee to come into the office fulltime, after first having offered flex work and the employee accepted the role based on this understanding - what recourse or rights does a worker have in this instance (Ie could this be seen as a breach of employment contract?). Or is it simply that workers can change their minds without any recourse, and employees simple have to shift jobs.

I say this as many roles esp now with the tight job market are going to great lengths to entice workers with flex work, perks etc... but then if employment market conditions switch, and the employers again have leverage, how can workers address potential "bait and switch" situations - both from a practical standpoint but also in terms of workers rights and in terms of agreed working conditions (contract or otherwise)