Solicitors

Union is a good call
With your issue you maybe could challenge without a solicitor at first?

 

As far as I can tell, the main grounds to contest it are along the lines of:

that it is invalid ie not witnessed, signed or incorrect information;
that the person was not of sound mind, or under duress;
that it doesn't meet the needs of legal dependents;
that there is another will.
I'm sure there'll be others and variances.

Whoever the other party is will most likely be keen to avoid the legal costs of defending a challenge, so maybe there's some room for mediation if you can make them believe you have a case?

 

I know a little about his claim, but not the detail.
Always worth a free ‘call your bluff’ letter first I’d think?

 

Without a doubt, but he needs to make sure he can cite the legal argument and has what appears to be a solid case.