A recent post from The Recusant posted in the SSPX/Rome Agreement subforum made a claim that 50% of all SSPX marriages in Europe are performed by an indult/novus ordo priest.

I would like to know if there is any factual evidence, docuмentation, etc to back that up.

If true, is this considered to be a pastoral concession to doubting/scrupulous couples?

Or is it the SSPX doubting the validity?

This was a most curious statement!

If the priest is not a valid priest, would the marriages be valid?

If the priest is not a valid priest, would the marriages be valid?

Tricky question.  As we know, the priest does not confer the Sacrament of Matrimony on the couple, but rather the couple confers it on each other, and the priest is merely there to witness the Sacrament for the Church, and to bless the union.

However, the Church has long required the presence of the local ordinary, the pastor, or a priest designated by them, or else the marriage is invalid.  This is a requirement of canon law, and is not divinely required, as I understand it.

With that being said, there are a number of exceptions to this requirement, such as if there is a lack of priests.  I'm not sure what the answer would be if the couple was married before a person claiming to be a priest, but in fact he was not.

If the priest is not a valid priest, would the marriages be valid?

Not necessarily true. Canon law requires that the priest have faculties to officiate at marriages. If he doesn't have faculties then the marriage is invalid.