Amarinder Singh joined the Bharatiya Janata Party (BJP) in 2022.
The Congress disciplinary committee on Friday suspended party's Lok Sabha MP Preneet Kaur and asked her to explain within three days why she should not be expelled for anti-party activities.
Congress' disciplinary panel member secretary Tariq Anwar said the action follows complaints against her from Punjab Congress chief Amrinder Raja Warring and other state leaders that she was helping the BJP in the northern state.
Former Union minister Preneet Kaur is the wife of former chief minister Amarinder Singh, who was ousted from the party and he later joined the BJP.
"The Congress president has received a complaint from Amarinder Singh Raja Warring, president of PCC Punjab, alleging that Preneet Kaur, MP (Lok Sabha) from Patiala is indulging in anti-party activities to help BJP. Some other senior Congress leaders of Punjab also share this view," Mr Anwar said in a statement.
He said the complaint was referred to the Disciplinary Action Committee (DAC) of the AICC for necessary action.
"The DAC carefully considered it and decided that Preneet Kaur, MP Lok Sabha from Patiala should be suspended from the party with immediate effect and she has been called upon to show cause within three days as to why she should not be expelled from the party," Mr Anwar, who is also the AICC general secretary, said.
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