“AUSTRIAN JUSTICE STINKS” read one of the placards held by a 40-strong group of protesters outside Wembley Synagogue on Sunday night.

The demonstrators were friends and family of Beth Alexander, an Orthodox Jewish woman from Manchester who lives in Vienna. A Cambridge graduate, Ms Alexander has lost custody of her three-year-old twins in the Austrian courts to her estranged husband Michael Schlesinger, who, she says, claims she is “mentally ill”.

Ms Alexander currently has only minimal contact with her sons Benjamin and Samuel and is unhappy about their development.

Mr Schlesinger was not available for comment.

Sunday’s protest was held outside a concert given by Vienna’s chief cantor Shmuel Barzilai. It was staged to help raise awareness of Ms Alexander’s case in the Austrian Jewish community.

Her supporters believe that if the rabbinate in Vienna put enough pressure on Mr Schlesinger, who was described by Ms Alexander’s brother Adrian as part of “a very powerful Austrian Jewish family”, he will return the children to their mother.

“We believe the Jewish community could be doing more,” Mr Alexander said. Another brother, Graham Alexander, said: “We’re very touched so many came from so far [to take part in the protest}. We just hope Cantor Barzilai will take the message back with him.”

Speaking before the event, Mr Barzilai said: “If someone from [the official Austrian community] was there I would understand, but it’s just me. I am only the cantor. I am very sorry about what happened, but I am just the cantor.”

Ms Alexander, who cannot leave Austria because she wants to maintain contact with her children, said: “This public display of support has made me more determined than ever to continue the campaign for justice for my little boys.”