The first answer is wrong. The staff handbook will form part of the terms and conditions of employment.
The second answer is misleading in that the requirement of the employer within 2 months (not 3) is to provide a written statement of employment particulars. It must contain at least the following:
your name and your employer’s name, your job title or a brief job description
the date when your employment began, your pay rate and when you will be paid
your hours of work, your holiday entitlement
where you will be working (if you are based in more than one place it should say this along with your employer’s address)
sick pay arrangements and notice periods
information about disciplinary and grievance procedures
any collective agreements that affect your employment terms or conditions
pensions and pension schemes
if you are not a permanent employee how long your employment is expected to continue, or if you are a fixed term worker the date your employment will end
What most employers that know what they are doing do is to cover this by a letter when you join and a staff handbook.
Whether or not you can make a case at ET if you don't have this I really don't know, though I'd be surprised if you can. You sure will endear yourself to your employer though. Depends if you want out, extracting the maximum amount of money, I guess.