Most people can sign an agreement as an individual to opt out of the 48-hour limit (and thus lose protection against working long hours). This must be an individual choice. There cannot be a collective or workforce agreement for everyone to sign away their rights. You also have the right to opt back in at any time.
Your opt-out agreement may contain the notice that is required for you to opt back in again. The longest it can be is three months. If there is no time limit, you can regain protection in seven days. If you are given an opt-out form with a three-month notice period, you may want to suggest that the notice period is shortened.
Note that there is no opt-out from the 48-hour limit on night work.
In addition, there is no opt-out for HGV and PSV road transport drivers or for inland waterways and lake transport workers. Separate rules apply to seafarers and air cabin crew.