Merav Ben Ari has Israel's most talked-about bump. The politician is pregnant, and the father is in a relationship with someone else.

But this is all part of the plan. A heart-to-heart talk with her mother left the lawyer-turned-legislator feeling that despite not having found a husband she wanted to become a mother. Which is when Ofir, her very close friend who is gay, came into the picture as the father.

"I'm a straight woman looking for a relationship but I didn't want to wait [for motherhood]," Ms Ben Ari says. "I really didn't have the time and didn't want to miss the opportunity." She raised the subject with Ofir, who was keen to father her child, and take an active daddy role after birth. The IVF process took time "and patience," and two years on, they are expecting a girl.

Discussing her plans between the flurry of meetings taking place ahead of the Knesset's winter session, which starts on October 31, she says that she already has a good picture of how the co-parenting will work. "We live very close [to each other] in Tel Aviv and will be like a couple who are divorced, are very good friends, and who live in two houses."

Ms Ben Ari, 40, decided that she did not want to return to Knesset after the long summer recess to find that her body started a "rumour mill," so went public about the background to her pregnancy.

Other women say they will do the same as me

Her announcement shone a spotlight on how more and more gay Israeli men are becoming fathers, some through arrangements between friends like this one, some through adoption, and some through surrogacy. Since the early 1990s, women - regardless of their marital status - have been eligible for state-funded fertility treatments. But while there have been plenty of lesbians raising children, it was only just over a decade ago that Israel started to see openly gay men fathering children.

Ms Ben Ari is a strong advocate for the LGBT community, and spent much of the first trimester of her pregnancy working on a new allocation of state funds for LGBT priorities. She represents the centrist Kulanu party, which controls the Finance Ministry, so her plan for 10 million shekels (£2 million) a year for LGBT education in schools, a new shelter for young Israelis who have been ejected from their homes because of their sexual identity, and other projects, is expected to go straight into the state budget. And given her political focus on LGBT issues, she is pleased by the publicity that her decision is generating.

She states happily: "I already got messages from women saying that I encouraged them to do the same or people who said that their friends or sisters were thinking about it and I'm an example that you can be a successful woman and do this."

What about the politicians of Knesset, a famously critical and argumentative lot?

She has received a "really good" response from fellow MKs, including members of Orthodox and Arab parties. "I got people from the coalition and the opposition who called to congratulate me," she says. "I didn't hear negative opinions. People encouraged me."

Ms Ben Ari commands an unusual level of respect in Knesset, especially given that both she and her party are newcomers to the chamber, only having entered in last year's election. Asaf Zamir, the deputy mayor of Tel Aviv, where she was a city councillor before entering Knesset, suggests that her appeal is the fact that she stays focused, and does not does not try to cover all political issues. "She's not one of those politicians who runs around all sorts of issues but, rather, she focuses on education, welfare, children at risk and LGBT issues," says Mr Zamir.

The National Union of Israeli Students has been quick to recognise her efforts, placing her top in its inaugural rankings, released in the spring, of how well legislators are tackling issues of importance to youth and students.

To anyone who knew Ms Ben Ari before she entered Knesset, her approach came as no surprise. Even as a teenager she was motivated. She started part-time work at 13, selling ice creams to earn pocket money, then in her twenties she served in the army for three years longer than she needed to. She then trained and worked as a lawyer and, in 2005, became a reality TV star in the service of at-risk children. It was a series called Seeking a Leader, in which activists competed for money to turn their social action vision into reality.

She won in early 2006, and was given five million shekels to turn her blueprint for at-risk youth centres into reality.

Ms Ben Ari set up two centres, one on Netanya and one in Herzliya, called Through Challenge, to help teenagers to build confidence and self-esteem through after-school tutoring and sports.

"We can show them that there is a way out - that they can be better people and achieve great things," she said shortly after setting up the centres.

With Through Challenge running well, in 2013, she joined Tel Aviv's city council and switched her attention to building programmes for that city's at-risk youth. But her tenure on the city council was short lived, because, when Moshe Kahlon, one-time ally of Benjamin Netanyahu, decided to break away from Mr Netanyahu's Likud and set up the Kulanu party, he was on the look-out for driven local politicians.

There are many uncertainties in Ms Ben Ari's life. Politically, she could be heading down. The latest polling suggests that the 10-seat Kulanu party could shrink to just six seats in an election, which means that if she keeps her current spot on the party list she would be out of Knesset. But polls change, lists change, and even party affiliations are fluid, so she could also be heading upwards, even to a ministerial post.

Whatever is up in the air, one thing is for sure: her baby, due to be born in February, is in for an adventure. One of the most energetic politicians, Ms Ben Ari is crazy about extreme sports, experienced in bungee jumping and scuba diving, and is just as at home trekking deep in the desert as drinking coffee in Tel Aviv. Mr Zamir fondly recalls political meetings with her when she had just returned from remote areas and she regaled him with details of her "escapades."

Ms Ben Ari says that she may tone down her travels a little but will certainly be taking her daughter on some exciting trips. "This is part of who I am."