future tense in a subordinate clause

Question

The following is an (outdated) article from the Guardian

Under the terms set before Tsipras, the Greek parliament has to endorse the entire package on Monday and then pass several pieces of legislation by Wednesday, including on pensions reform and a new VAT regime, before the eurozone will agree to negotiate a new three-year rescue package.

I read before that the present simple is often used for future time in a clause with before when both clauses are about the future. Is it possible to substitute agrees for will agree? If so, what is the difference in the meaning?

Answer 1

In my reading, this is not the future "will" it is used here in the sense of willingness.

"... before the eurozone will agree..." <---> "... before the eurozone is willing to agree ..."

Answer 2

No you definitely cannot, and this is one of the rare occasions when the distinction is both visible and important. Before the eurozone agrees would refer to a deadline: ...before the creditors meet on Wednesday to agree the rescue package. The understood but omitted phrase would be something like "After that it will be too late". Before the eurozone will agree a rescue package is not imposing a deadline, merely an ultimatum. I think the jopurnalism here is clumsy, but the grammar is clear.