if the contractor's contract with his employee says he will be paid for non-working time (such as travel to site, or lunch breaks, or days hanging round the office when there is no work to do, or bank holidays, or sick leave, or training days) that is not relevant to what the client has to pay.
The client pays what is in his contract with the contractor. Clients are unlikely to agree to pay for non-working time in their contact, and even more unlikely to pay for it if it is not in their contract.
The daily or hourly rate to the client has to take account of the contractor's costs, including pensions, holidays, non-working time, employer's NI etc, which is why the "wages" might be £x per hour but the client's charge rate may be £2x per hour.
The client pays what is in his contract with the contractor. Clients are unlikely to agree to pay for non-working time in their contact, and even more unlikely to pay for it if it is not in their contract.
The daily or hourly rate to the client has to take account of the contractor's costs, including pensions, holidays, non-working time, employer's NI etc, which is why the "wages" might be £x per hour but the client's charge rate may be £2x per hour.