He is returning to Parliament to continue with his duties as he is still a sitting MP

He has only been arrested, and bailed until mid June, on suspicion of the alleged charges.

So unless or until he is formerly charged with the offences, tried and found guilty, he is free to continue his work and life.

I don't think this has changed yet:

At present, MPs are disqualified from Parliament only if they are sentenced to a prison term of more than 12 months.

There were plans to strip convicted MPs of more than their seat in Parliament for other, non-custodial sentences and for constituents to sack their MPs for any conviction.