Politician Kim Leadbeater the sister of murdered MP Jo Cox, has said collecting her MBE at Windsor Castle for her work tackling social isolation was “bittersweet”.

The Labour MP described Tuesday’s investiture ceremony, during which she received the honour from the Princess Royal as “beautiful”.

She told the PA news agency: “Any occasion that I attend, particularly something of this magnitude, for me is always bittersweet, because ultimately, the fundamental reason I’m here is because of Jo’s murder.

“So it’s an emotional day as well, but I also know that Jo would be incredibly proud of everything that we’ve done in her name.”

Her sister Jo Cox was killed in 2016 when she was shot and stabbed by a neo-Nazi outside her constituency surgery a week before the EU referendum.

Ms Leadbeater said she would celebrate the honour by doing Zoom calls with her parents and her sister’s children to “show them that Auntie Kim has been to Windsor Castle, was thinking about mummy and them”.

She has represented the same seat occupied by her sister, Batley and Spen, since winning a by-election last summer.

She has championed the issues Mrs Cox had been passionate about, including fighting social isolation through the More In Common initiative and Jo Cox Foundation.

She said: “I’m so incredibly proud of those first few years of the Jo Cox commission on loneliness and the results of that in that we’ve got the world’s first ever minister for loneliness – Tracey Crouch MP”.

Ms Leadbeater stepped up her efforts during the coronavirus pandemic as millions faced loneliness due to lockdowns, including setting up a national coalition of hundreds of organisation that joined forces to address the issue.

In her West Yorkshire constituency, she helped deliver food and medicine to people in need.

The MP said: “It’s not just psychological damage that loneliness can do, there’s a physical impact as well.

“The research that we did through the Jo Cox commission said that it’s as dangerous as having 15 cigarettes a day.”

Ms Leadbeater said she has just signed up to co-chair the All Party Parliamentary Group on loneliness and connecting communities, and is also focusing on issues such as mental health, education and children’s health and wellbeing in Parliament.

She has previously called for MPs’ safety to be taken more seriously in the wake of her sister’s murder, as well as that of Sir David Amess who was stabbed to death while he held a constituency surgery in October.

Asked whether she felt safe as a politician, she said: “I think we’ve seen some positive steps in the area of MPs’ safety, but I think there is more work to be done.

“I have to say, the vast majority of time I feel fine, but that’s because I’ve taken all the help has been offered.”

She went on to say: “I think there’s this broader piece of work to be done around why people are so angry, and why we find it acceptable to take that anger and frustration out on the next person that we come across, whether that’s an MP or whether it’s a nurse or a taxi driver.

“And I’ve often said, I’m extremely angry about what’s happened to my life, but what I try and do is channel that anger into doing something positive and trying to make a positive difference.”