A man has been charged with malicious communications after deputy Labour leader Angela Rayner received a series of threats and abuse.
Police also said they made a third arrest on Thursday over the phone calls, emails and letters that the MP for Ashton-under-Lyne reported receiving in recent weeks.
Benjamin Iliffe, a 36-year-old from Cambridgeshire, was charged with malicious communications and possession of cannabis and was due to appear in court, Greater Manchester Police said.
GMP said a 70-year-old man was arrested in conjunction with South Yorkshire Police on suspicion of malicious communication and remained in custody.
He was arrested in relation to emails received on October 16, while a 52-year-old was arrested in Halifax, West Yorkshire, and bailed over abusive phone calls Ms Rayner received a day earlier.
Ms Rayner, a mother of three who is on bereavement leave after losing a close loved one, reported receiving the threatening contacts over a number of weeks.
After the first arrest, her spokesman said: “Abuse and threats of this nature don’t just have an impact on Angela but also on her family, her children and her staff who are on the receiving end of these communications.”
The investigation by at least three police forces comes amid increased concern over the safety of MPs and the level of abuse they receive following the killing of Sir David Amess.
The veteran Conservative MP for Southend West was stabbed in a suspected terror attack during a constituency surgery in Leigh-on-Sea, Essex.
Iliffe, of Slade Way, Chatteris, was due to appear before Huntingdon Magistrates’ Court later on Thursday.