"Employment Rights" for Umbrella Employees

[lucyclarityumbrella]

Assume the end client has 60 day payment terms and settles the May invoices on July 28th

Depends on whether the brolly has transfered the payment terms down the chain to you via an assignment schedule that you accepted? If they do not transfer the agency terms to you then you should be paid on the terms they stipulate in the contract.

[lucyclarityumbrella]

"My employer's terms with their client are nothing to do with me. I work for my employer and they should pay at least the minimum wage for hours worked at the agreed frequency (monthly)

They should yes, if the invoice is overdue ie past agreed payment terms that have been passed down to you via the schedule. Then assuming the contract states guarantee of Minimum Wage, then this would be due.

[lucyclarityumbrella]

The brolly is saying that, legally, they don't have to pay me if their client does not (or cannot) pay them.

Not true if the invoice is overdue, then you are correct in stating that you are due payment (assuming its in their contract which it should be), then minimum wage would be due.