Around 100 Orthodox rabbis from across the country are expected to gather at a conference at the weekend convened at short notice by leading outreach organisations.

In an invitation to one rabbi issued only at the end of last week, Rabbi Naftali Schiff, the executive director of Aish, which has organised the event jointly with the Jewish Learning Exchange and Project Seed, said that "Orthodoxy UK is on a back foot at present."

Rabbis from the United Synagogue, Federation and regional congregations have also been invited to the event, which runs from Sunday night to Monday.

Rabbi Schiff wrote that there was "a lack of joined-up thinking, achdus [unity], strategy and even knowledge of who is who, and what is going on across the gamut of kiruv [outreach]".

The gathering comes just a week after the end of the annual Limmud conference attended for the first time by Chief Rabbi Ephraim Mirvis and the largest ever delegation of United Synagogue rabbis.

The chief rabbi's decision to go exposed divisions among the rabbinate and prompted an outspoken attack on Orthodox participation in Limmud from the former head of the London Beth Din Dayan Chanoch Ehrentreu and the leadership of the Gateshead community.

But Rabbi Schiff said this week that the event was "not at all" connected with the debate over Limmud. "This is not a topic for discussion. There will be rabbis and rebbetzins who have, and who have not attended, Limmud. This conference is about that which unites us, not divides us."

He explained; "So much of how Orthodox rabbis and Orthodoxy comes across is what we're against. Change is upon us and the challenges are great. Hence the need to meet and discuss many varied issues. It's time we stopped being reactive and spoke up about what we are for and what we are proud of."

In the 1990s, outreach organisations were instrumental in launching the one-day Encounter conference, which was seen as an Orthodox alternative to Limmud, but the initiative folded in 2005.

Asked whether the forthcoming event was a prelude to a revival of Encounter, Rabbi Schiff said "No,this is a seminar for rabbis on the subject of outreach. We don't know where it will lead."

The organising group have called themselves Aleinu and their initiative, Rabbi Schiff said, was "an extension of the successful collaboration and increased partnerships formed between JLE, Aish and Seed over recent months and years."

The keynote speaker is Rabbi Avraham Edelstein, the founder of an educational institute Ner Le'Elef in Israel. Two dayanim from the London Beth Din are due to attend the event, which was been titled "Working together for ensuring Jewish futures".

One United Synagogue rabbi, Jonathan Hughes of Richmond Synagogue, who was planning to go, said he understood that the "primary goal is to increase a sense of unity and purpose across the rabbinate."

Rabbi Hughes believed that "we are living in a time of polarisation. The Charedim are becoming more Charedi, the left more staunchly left. It is challenging to be in the middle of the road."