A Labour candidate has said she will not be intimidated after her office was attacked and “malicious and false leaflets” were circulated.
Stella Creasy posted pictures of the attack on her office in Walthamstow, northeast London, where she is fighting to keep the seat she has held since 2010.
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A window and glass door had several holes in them and there were cracks across the glass.
Police said they believe the office was targeted between 3.10am and 3.30am on Sunday.
Ms Creasy also said “malicious and false” leaflets have been handed out.
Ms Creasy wrote on social media: “Message to whoever attacked my office last night.
“You don’t intimidate me and you don’t belong in the political process.
“Same as those circulating malicious and false leaflets.
“Police already on this to find you – will press for the strongest penalties for such an anti-democratic attack and I know Walthamstow won’t be cowed or influenced by your violence either.”
A Labour spokesman told Sky News: “We completely condemn any intimidation tactics towards candidates of any party.
“It is vital to our democracy that parliamentary candidates are able to campaign freely.”
The Met Police confirmed an investigation has been launched into criminal damage at Ms Creasy’s office.
Detective Superintendent Dion Brown, one of the senior officers responsible for policing Waltham Forest, said: “It is entirely unacceptable for the office of one of London’s prospective parliamentary candidates to be targeted in this way.
“An urgent investigation is underway, and officers have attended the scene and are already following up active lines of enquiry, which will include full analysis of all available CCTV footage.
“The incident is believed to have occurred between 03:10hrs and 03:30hrs on Sunday, 23 June. I urge any witnesses or anyone with information to contact police and share what they know.”
Anyone who witnessed the damage being caused, or who has other information, should call police on 101 with the reference 2621/23jun.
Ms Creasy was a frontbencher under Ed Miliband and Harriet Harman when they were Labour leader and acting leader, respectively.
The 47-year-old has been a vocal critic of Jeremy Corbyn and said the party under his leadership was “running on empty”.
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Ms Creasy received numerous rape threats and other misogynistic messages on her Twitter timeline in 2013 after supporting feminist campaigner Caroline Criado Perez, who lobbied the Bank of England to put a woman on the £10 note.
Last year, Ms Creasy revealed she had been investigated by her local council after a man using an alias complained her “extreme views” would damage her children and they should be removed from her.
The complaint was dismissed and the man, who had no personal connection to Ms Creasy or her children, apologised.
The other candidates standing in Walthamstow are:
Imran Arshad, Workers Party of Britain
Mohammed Ashfaq, Independent
Dan Edelstyn, Independent
Sanjana Madan Mohan Karnani, Conservative Party
Martin Lonergan, Reform UK
Ruth Theresa Rawlins, Independent
Rosalinda Ayo Rowlands, Green Party
Nancy Taaffe, Trade Union and Socialist Coalition
Rebecca Taylor, Liberal Democrats