JNF UK's most successful fundraiser has decided to quit the organisation after 15 years and instead work for the UJIA.

Harvey Bratt, 53, the head of JNF's legacy department, said that he was "looking for a new challenge at this stage in my career. My passion is community, charity and Israel, so there was only one logical choice."

Mr Bratt's value to JNF – which has been striving to rebuild its image following a series of controversies in recent years – is obvious from the figures: in 2009, the charity received £3.9 million from legacies, compared to £3.1 million from other donations.

Former JNF UK president Gail Seal said that UJIA must be "thrilled" to have recruited Mr Bratt, and added that JNF would find it "very difficult" to replace him. "He is brilliant at what he does. It's a very specialised job," she said.

Mr Bratt will move to the UJIA in 2012 to assume the new post of legacy director. UJIA chief executive Douglas Krikler said: "We were delighted to be approached by Harvey at a time when UJIA is looking to strengthen our legacy campaign."

Mr Bratt's face is missing for the first time this week from a long-running JNF advertising campaign which emphasised his personal touch. He said that he had asked for his image not to appear because it made sense now to "shift that focus".

He added: "Nobody's indispensable and JNF is strong enough to withstand a departure of a member of staff."

JNF chief executive David Goodman, thanking Mr Bratt for his "dedicated service", said that the process of recuiting a new legacy director had begun. "We have been gratified to identify a number of interesting candidates who we believe will have the skills, energy and enthusiasm to re-energise and grow this important department".

Meanwhile, Mr Goodman said that he and his colleagues were working "to ensure that our many clients continue to receive the professional legal services and high levels of pastoral care they have come to expect".

The UJIA is keen to boost its income from wills, having raised a mere £302,000 from that source last year. Over the four years from 2007 to 2010, its legacy income amounted to around £2.7 million – more than a £1 million less than the JNF's legacy haul in a single year.

But despite the difficult economic climate, UJIA has arrested the slide in its income. Its newly available accounts for 2010 show that income from donations and legacies was up from £12.6m in 2009, to £13m last year.