Given that there are about 800 cancer charities in the UK, this sounds an ambitious aim. But Ellis is confident. "I see no reason why we cannot fulfil our potential and become one of the biggest charities in the country," he says. "We want to make a difference to every family whose children are affected by cancer."
Trying to achieve this level of recognition will be a challenge, particularly given that the new name doesn't exactly say what it does on the tin. "We gave it a lot of consideration and thought about changing it to Cancer Care for Children," Ellis explains. "This is now the strapline, but it doesn't really sum up what we do either. We work with teenagers, too.
"You can't get across everything we do in one statement. So we asked our staff and supporters about it, and they said it was important to recognise all the work that the two charities have already done."
Ellis hopes that Clic Sargent will eventually become synonymous with the work it does. He says: "Most people don't know what Oxfam stands for; nor does Virgin explain what that company does. We decided to take a generic name and make it known for what it stands for. We need to be known by our brand, not restricted by the limits of the English language."
Choosing the name and a new puce logo was, according to Ellis, the only difficult part of the merger. Clic and Sargent have been running complementary services for about 30 years, and research has shown that families want a 'one-stop shop'. He says: "Some people even said we were like one organisation anyway, and it had been talked about for some time. We finally started to discuss it seriously last summer and, with both charities at a similar size and financially stable, concluded it was a good time to merge. It was important that it was a meeting of equals and not a takeover."
Ellis says about 10 staff have lost their jobs because of duplication, although he emphasises that every effort is being made to find them roles in the merged body. Where two people were, in effect, doing the same job, both were interviewed to decide who should stay - this included personality assessments that were drawn up using third party advice. Among those for whom the merger has not been such good news, however, is Siun Cranny, the former chief executive of Sargent. According to Ellis, she is "in talks about her options".
In general, however, Ellis is convinced that the benefits of the merger far outweigh the pitfalls. He is hoping that, by combining resources, the new charity will be able to raise £17m in its first year. He says: "We can minimise our overheads and maximise our services so that we can reach families in every part of the country - at present, we have more services in some parts than others. We can also wield more influence over decision-makers because, rightly or wrongly, they are more likely to come to a larger organisation. It's a competitive environment, and we want to recruit and retain the best staff we can."
Given that Charity Commission chair Geraldine Peacock has claimed there are too many charities pursuing the same aims, it is not surprising the merger has been strongly supported by the commission.
But as Ellis points out: "You have to look at each possible merger on its own merits. I don't support change for change's sake - we must stay focused on the fact that this is for the children who need our services."