For 25 of the group of 34 twenty-somethings setting off from Luton airport to Ben Gurion, a first experience of Israel awaits.

Many of the diverse group for the latest UJIA Birthright trip - for those who have never visited Israel on an organised teenage tour - are going with an open mind, if a minimal understanding of Judaism or Israeli politics. Others have hitherto shunned their Jewish identity and are looking for ways to reconnect.

There is even a young mum bouncing her baby on her knee. Welsh-born Laura Scarrott has converted to Judaism and is a member of West London Synagogue. She maintains a long distance relationship with the Israeli father of her daughter, whom she met on a previous trip to the country. She will drop off baby Seren at his home before rejoining the group.

For Ms Scarrott, 24, Birthright is particularly important as it marks her first visit to Israel since undergoing her Reform conversion in 2013. Now living in West Hampstead and working in human resources, she goes to synagogue every week.

"Ever since I was a kid, Judaism has been my favourite religion, she says. "I've always been tied to it. There was nothing that made me think that way, I just naturally did. I went to a Church of England school but my mum was very open and introduced me to a lot of religions.

"The best thing my rabbi told me was that my conversion was the start of my Jewish journey and every encounter with Judaism would further my journey. That's one of the reasons I wanted to come on this trip.

"I'm learning from absolutely everything. I have learnt more about the differences between Orthodox and Reform Jews; Ashkenazis and Sephardis; people who are religious and who are not."

For Lily Sutton, the experience is also about meeting Jewish people. The 26-year-old, whose brother, Alfie, 24, is also among the group, was born to a Jewish mother and non-Jewish father in the Midlands town of Evesham. This is their first visit to Israel.

"I have always known I'm Jewish," she explains. "My mum went to JFS and she is quite Jewish in her mannerisms, but my brothers and I know very little about Judaism. There were no other Jewish people where we grew up.

"In the past couple of years I have met a few people who have gone and sung UJIA's praises - and this would have been my last opportunity to go before I turn 27 [the cut-off age is 26]."

After the 10-day trip, Ms Sutton intends to meet up with other participants and to host Shabbat dinners.

She had been attracted by the prospect of meeting "like minded Jewish people that I didn't feel intimidated by - and I have done exactly that. I've met other girls who have a Jewish mum, non-Jewish dad and who grew up in a non Jewish area.

"I have met people I can connect with. I want to be able to do more Jewish things."

For Manchester-born Alastair Frankl, 24, the tour has been about reconnecting with the Jewish identity he turned his back on as a teenager. The former King David Primary pupil was raised in a synagogue-going family and grew up "quite Orthodox".

But at Manchester Grammar, he decided to distance himself from Judaism. "I did not like the fact that I grew up in this bubble. I was not exposed to the multicultural side of life."

He also "didn't like the boys I grew up with and that is what I associated being Jewish with. They were all footballers with slicked back gelled hair. That was one of the big reasons I disengaged with it all."

After his barmitzvah, "my mum gave me the choice to follow the religion as I wanted. I lost touch with it. I didn't go to synagogue.

"I didn't keep much of Rosh Hashanah or Yom Kippur. Part of being here in Israel is about getting back in touch with the religion."

The app designer was prompted to rediscover his background by going out with his first Jewish girlfriend - they have just celebrated their first anniversary together.

And the tour has surprised him in a positive way. "I thought I would hate it. I thought they would tell me what to think and do, but it's not like that. It's educational."

During a visit to the Golan Heights, he laid tefillin, an "amazing" experience.

"I was so calm, so relaxed. There was no judgement. I decided that while I am in Israel I am going to put on tefillin every day."

He felt "really comfortable to walk around in a kippah, whereas in Manchester, I would not be comfortable because Chasidic people would look at me [because he was not as religious]. Here, some people wear one, some people don't; some people are Chasidic, some aren't. It doesn't matter."

Mr Frankl plans to return to Israel this winter to visit family in Tel Aviv and now says that when he has a family, "I would bring them up in the same way I was.

"Full kosher home, synagogue every week. I rebelled but they will be given their own choice to follow the religion as they want."

The admissions criteria is defended by David Neifeld, UJIA's Birthright and Israel engagement co-ordinator.

"To come on this, you cannot have been on an organised tour to Israel since you were 12," he explains.

"The reason we run this trip is for people to engage with their Jewish identity and Israel. People come back and want to get engaged with the Jewish community, whether it's the religion, the heritage or the culture - right across the spectrum."

"It's not about a free holiday. It's a completely different experience to coming with your family. You may have come many times with your family but it doesn't provide the insight and structure that we do. We go right across the country and show different points of Israel.

"There are certain people who did not have funds to go on a tour, or maybe they didn't want to - maybe they were going through a period of not wanting to be involved in Israel but now they do."

In addition to visiting "the typical tourist places", the itinerary included UJIA projects, for example, a co-existence kibbutz where participants can meet both Jews and non-Jews.

"Obviously there is a limit to what we offer. We can't go into certain places, like the West Bank or East Jerusalem. We provide the most we can possibly offer within the security framework and can fit within a 10-day period. If people want to come back and explore further, we can point them in the relevant direction.

"It's not a political point we are making."

UJIA invests around £250,000 in the programme each year. Most of this is to fund one third of the cost of each participant's trip - the remainder is covered by Taglit-Birthright Israel and the Israeli government.

The UJIA contribution also encompasses follow up activities and the cost of tour leaders and training.