Ministers might be so relieved that their congregants are planning to marry within the faith that they might be reluctant to criticise the wedding arrangements.

But extravagant celebrations fly in the face of traditional modesty, according to the head of a major north London United synagogue, speaking on condition of anonymity.

"People are falling into the trap of putting their families on show," he says. "More resource and thought should be put into how to help the couple prepare for their new life than the actual day. That offends me as a rabbi.

"People should come to their senses. Do your children need a wedding that costs £100,000, or are you showing off? It makes people jealous and it could force people to spend more money than they could afford."

When the opportunities for kosher venues were limited, couples got married in synagogue. But many now decamp to smart hotels in the centre of town that have opened their doors to supervised caterers.

"You get the feeling it's done more to say 'we had it in the West End'," the rabbi observes.

In his view, importing singers from abroad, or going overboard on flowers, are among needless expenses. "One band is not enough - you have a band for the Jewish music and another band comes in for the jazz or rock." Or there are frills such as lookalikes (though this is more prevalent at barmitzvahs). "I have been to a wedding where the 'Queen of England' was there."

He is also exasperated by the increasingly sophisticated filming of weddings. "I am surprised how many cameras there are. You get the feeling you are on the set of a TV series.

"Sometimes the rabbi or whoever is under the chupah feels pushed out because they come in with these big cameras, sometimes with a boom. Not only that but the guests sometimes can't see what is going on because the cameramen are standing right in front.

"Then you have people holding up their phones. I have had people blocking their aisle because they want to get pictures on their smartphones."

No rabbi he is aware of has taken the "extreme measure" of refusing to officiate at an over-the-top function. But in Israel, particularly within some Chasidic communities, "there are some rabbis who will limit how many guests you can invite. They can't limit how much you can spend."

While some colleagues feel it a "lost cause", he believes rabbis should be trying to discourage excess.

At the very least, hosts should be invited to consider making a charitable contribution equivalent to five per cent of the wedding costs (for example, £2,750 based on our calculation of a "normal" kosher wedding costing £55,000).