Bill Clinton will return to the campaign trail next week to fundraise for his wife Hillary Clinton, as her campaign aims to turn the corner on what has shaped up to be a disappointing summer for the Democratic frontrunner, according to media reports.

The former president, who has been virtually absent from the 2016 campaign trail, will appear at a fundraiser in Chicago on 17 September, according to the New York Times and other media outlets.

His return comes as Hillary Clinton’s campaign attempts to turn the page after a summer that showed new vulnerabilities for a candidate whose victory in the Democratic primaries was once thought to be a foregone conclusion. For months, Clinton’s campaign has been dogged by her controversial decision to use a personal email server during her tenure as US secretary of state. She has also ceded ground to fellow Democratic contender Bernie Sanders, who has made gains on the frontrunner in New Hampshire and Iowa, while contending with the improbable candidacy of Donald Trump on the Republican side.

Clinton has struggled with how to respond to the long-simmering controversy over her email server following the revelation earlier this year that she had used a personal email account set up at her home in Chappaqua, New York, to conduct government business. Clinton was criticized for mocking the scandal surrounding her email system during a campaign event in Iowa last month, and for responding to a reporter’s question with a sarcastic retort asking if wiping a server was done “like, with a cloth or something”.

Last week, she told the Associated Press she did not need to apologize for using a private email server because “it was allowed”, echoing statements she had made earlier in which she said she was “sorry” for the confusion caused by the scandal while emphasizing that what she did was legal.

Last year, Clinton turned over roughly 55,000 pages of emails to the US State Department, while deleting more than 30,000 emails from her server that her lawyers said were personal. The State Department is in the process of vetting the emails, and publicly releasing them in tranches, with a stated goal of releasing them all by 2016.

A second review by US intelligence investigators has shown that at least two of Clinton’s emails contained “highly classified information”, according to a report in the New York Times. The Clinton campaign had disputed an earlier review that determined that some emails contained classified information. Clinton’s campaign again disputed the findings, contending that different agencies had different approaches regarding what information should be classified.

There were also reports that Clinton’s campaign is reworking its strategy to show off more of the candidate’s softer, more relatable side.

According to the New York Times, she will spend more time talking to media outlets, with an emphasis on non-traditional ones. She is scheduled to sit down with ABC’s David Muir on Tuesday, in her third nationally televised interview since launching her campaign in April. She is also due to appear on The Ellen DeGeneres Show and on The Tonight Show with Jimmy Fallon.

On Tuesday, Clinton unveiled a new campaign finance proposal, which would require companies to disclose their political donations. Clinton has said if they cannot pass this, she would support a constitutional amendment to overturn the supreme court’s controversial 2010 Citizens United decision, which in effect opened the floodgates to unlimited political spending by billionaire donors.

Campaign finance reform is a central plank of Sanders’s campaign. The Vermont senator has eschewed Super Pacs – which are independent of the candidates’ campaigns and which, unlike the campaigns, may raise unlimited amounts of money from individual donors – in favor of small campaign donations. Clinton has used the current campaign finance laws to her benefit, hosting several high-dollar fundraisers and benefiting from her Priorities USA Action Super Pac. She and her aides have maintained that a Super Pac is necessary to compete with the massive amounts of funding raised by Republicans, and that they will make changes to the system after winning the election.

“We have to end the flood of secret, unaccountable money that is distorting our elections, corrupting our political system, and drowning out the voices of too many everyday Americans,” Clinton said in a statement on Tuesday. “Our democracy should be about expanding the franchise, not charging an entrance fee. It starts with overturning the supreme court’s Citizens United decision, and continues with structural reform to our campaign finance system so there’s real sunshine and increased participation.”