The man accused of murdering Labour MP Jo Cox researched Conservative MP Ian Grow – who was previously the last serving politician to be killed in the UK – in the days before her death, a court has heard.

Thomas Mair, 53, is also alleged to have shouted "Britain First" and researched several far-right sites such as the Klu Klux Klan (KKK) before shooting and stabbing the MP for Batley and Spen outside her constituency surgery in Birstall, near Leeds, on 16 June.

Mair denies the charges of murder, grievous bodily harm, possession of a firearm with intent to commit an indictable offence and possession of an offensive weapon. He is also charged with causing grievous bodily harm with intent to Bernard Carter-Kenny, who was injured while attempting to intervene in the attack.

During the first day of his trial at the Old Bailey, the jury heard that Mair used the computers at the Birstall library close to where Cox was killed to research the MP.

Mair is said to have looked at Cox's Twitter and Wikipedia page, as well as that of Tory MP Gow, who was murdered by the IRA in a car bomb attack outside his home in east Sussex in 1990.

Prior to Cox's death, Gow was the last sitting British MP to be murdered. Mair is also accused of researching .22 gun ammunition, including asking: "Is a .22 round deadly enough to kill with one shot to a human head?"

The court heard how Cox had died after being shot three times and stabbed 15 times during a "cowardly" attack.

Outlining the case, Prosecutor Richard Whittam QC said Cox's death was a "a planned and pre-meditated murder for a political and/or ideological cause".

The trial continues.