Can i work 45 hours per week in two jobs

[djones123]

Hi,

I am planning to join a new company on 37.5 hours a week contract and also i am planning to do 7.5 hrs a week with my current employer for few months.

Is it legal to do more than 37.5 hours a week?

As far as tax is concerned, I think I will be paying 40% tax on both jobs as tax on main job (37.5 Hrs) is 40%.