After his graduation in 2001, Mackintosh worked as a political counsellor in the European Parliament until 2004, before leaving to assume a post at Conservative Campaign Headquarters as a political consultant to the Conservative Party. He was elected to Northamptonshire County Council for Ecton Brook on 4 June 2009 and to Northampton Borough Council for Rectory Farm in 2011. In May 2010, Mackintosh was appointed as Cabinet Member for Strategy, Communications and External Relations. He had previously held the position of Assistant Cabinet Member for Leadership and Strategic Support. He served as leader of Northampton Borough Council – the youngest the council has ever had – from November 2011 until his election to parliament. In addition, he served as cabinet member for Community Services. Mackintosh was opposed to Brexit prior to the 2016 referendum. Mackintosh was facing the prospect of being deselected by his local party, but he announced he would not stand in the June 2017 general election.
Controversies
Sale of Sekhemka statue
In July 2014, while Leader of Northampton Borough Council, Mackintosh was responsible for the controversial sale of the Sekhemka statue which led to the Arts Council removing accreditation from the Northampton Museums. The Ancient Egyptian statue had been given by the Marquess of Northampton to Northampton Museum around 1870. Mackintosh was awarded the title "Philistine of the Year" by Private Eye magazine for approving the sale of the statue, which the Save Sekhemka Action Group called the "darkest cultural day in history".
When Mackintosh was leader of the borough council, the authority made a £13.5m loan to Northampton Town football club, intended to pay for improvements at the club's Sixfields Stadium, including a new east stand. However, the project collapsed with £10.25m owed to the council. In November 2015, both the BBC and The Guardian newspaper reported that Howard Grossman, the director of a company responsible for rebuilding Northampton Town's Sixfields Stadium, had provided a £6,195 undeclared payment to Mackintosh's election campaign. Three other businessmen, with links to Grossman, each reportedly made donations of £10,000 to Mackintosh's campaign; one of them admitting to a journalist that he was given the money by Grossman and instructions to pay it to Mackintosh's parliamentary campaign fund. In September 2013, while Mackintosh was still leader, the council had provided an unsecured loan to the company which went into administration owing them millions of pounds. The BBC reported that the police had started an investigation into alleged irregularities surrounding the loan. On 29 July 2016, Northamptonshire Police confirmed the Electoral Commission had asked them to investigate the three donations totalling £30,000. On the 28th of March 2018 the BBC reported that Mackintosh had attended a voluntary interview with police under caution on Monday the 26th of March 2018. The BBC also reported that whilst attending the interview police officers attended Mackintosh's home for several hours and took items away.
