Nicola Sturgeon has claimed the crisis surrounding the Scottish National party’s “fractious” leadership battle is a necessary part of its renewal, in her final speech as party leader. Speaking at the Royal Society of Arts (RSA) in London, Sturgeon said the leadership contest sparked by her decision to resign was “proving to be a challenging and difficult process”, but denied it would cause longer-term damage to the SNP’s fortunes. It was “a moment to change, refresh and renew”, she said, downplaying the significance of the crisis. Sturgeon’s remarks followed one of the most bruising periods in the SNP’s history after her husband, Peter Murrell, was forced to resign on Saturday morning as its chief executive after the party’s national executive warned he faced a no-confidence motion he was certain to lose. The NEC’s revolt came after the SNP’s head of communications at Holyrood, Murray Foote, quit on Friday after learning he had unwittingly lied to the media about a steep and sudden slump in the party’s membership figures. Murrell, who along with Sturgeon and her predecessor Alex Salmond, had shaped and dominated the party for 20 years, had been resisting intense pressure from the leadership candidates Ash Regan and Kate Forbes to disclose how many members could vote in the election. Regan in particular has implied the voting process may not be fair and transparent, with her allies suggesting the voting firm involved was not sufficiently independent – allegations Sturgeon has repeatedly denied. Foote had been told to rubbish what turned out to be accurate media reports that its membership had slumped by 30,000 in the last year. On Thursday, the SNP acknowledged that only 72,000 members could vote – nearly 32,000 fewer than the last official membership figure. In an interview with ITV News earlier on Monday, Sturgeon claimed she did not know 30,000 people had quit the party in the past year and implied her husband had not passed that information on to her. She said Murrell had inadvertently misframed the response to media inquiries on that figure. Sturgeon was not directly challenged about that issue at the RSA but was asked about admissions from Mike Russell, the party’s honorary president and interim chief executive, on Sunday that the party was in a “tremendous mess” over the leadership contest. She said the SNP rarely staged leadership contests and had only had three people lead it over the last 30 years, implying it was out of practice. “It’s proving to be a challenging and difficult process, but it’s a necessary process to embrace change and make a transition,” Sturgeon said, as she began her last week in office before being replaced as SNP leader in a week’s time. “[This] is an unusual process for the SNP but it’s essential and it’s healthy, and, while it might not feel it right now, it will, I think, lead to a stronger position as we come out of it.” It was essential, she added, that the party focused on its strength at Holyrood, its election-winning machine and its polling lead, and remembered its mission, rather than focus on the present crisis. “Getting that balance right is important, and be careful not to throw the baby out with the bathwater,” she said. Over the past few weeks, Sturgeon’s political legacy and her policy agenda, on the climate crisis, on gender recognition and equalities, on her power-sharing deal with the Scottish Greens, on the quest for Scottish independence, has come under at times concerted attack by contestants to succeed her. The last opinion polls were carried out a week ago, before the latest crisis, but they showed support for the SNP in a Westminster general election had dipped to below 40% for the first time in several years – leaving it only 10 points ahead of Scottish Labour.