Amarinder Singh had blamed Mr Sidhu for party's poor performance in urban areas in Lok Sabha polls.

Highlights Navjot Singh Sidhu sent his resignation letter to Amarinder Singh today

Mr Sidhu had resigned as a minister a month ago

Mr Sidhu has been embroiled in a feud with Amarinder Singh

Navjot Singh Sidhu, who resigned as Punjab minister a month ago, sent his resignation letter to Chief Minister Amarinder Singh today. "There has to be some kind of discipline," the Chief Minister fumed, indicating that he had yet to read Navjot Sidhu's letter delivered to his home in Punjab.

Mr Sidhu tweeted that his resignation "has been delivered at the official residence" of Amarinder Singh, aka "Captain".

News that he had resigned from the Punjab cabinet, not now but a month ago, was revealed when the cricketer-turned-politician shared a letter he had submitted to Rahul Gandhi on June 10. The 55-year-old leader had met Rahul Gandhi and his sister Priyanka Gandhi Vadra in Delhi after he lost key portfolios in a cabinet shuffle following his public spat with Amarinder Singh.

My letter to the Congress President Shri. Rahul Gandhi Ji, submitted on 10 June 2019. pic.twitter.com/WS3yYwmnPl - Navjot Singh Sidhu (@sherryontopp) July 14, 2019

Met the congress President, handed him my letter, appraised him of the situation ! pic.twitter.com/ZcLW0rr8r3 - Navjot Singh Sidhu (@sherryontopp) June 10, 2019

Mr Sidhu had skipped cabinet meetings over the past few weeks but even his boss appeared to have learnt about his resignation only from Twitter on Sunday.

"Let me read Sidhu's letter first, then I will react," Amarinder Singh told reporters in parliament, where he had come for a meeting with Prime Minister Narendra Modi.

The Chief Minister reshuffled the state cabinet in the first meeting after national elections on June 6. He took away the Local Government portfolio from Mr Sidhu and assigned him Power and New and Renewable Energy Sources. Mr Sidhu's other portfolio of Tourism and Cultural Affairs was also taken away.

On the Congress's national election tally in Punjab - eight out of 13 -- Amarinder Singh said the party failed to do well in urban areas because Mr Sidhu had handled his portfolio poorly.

"We have 17 ministers. I changed the portfolio of 13 ministers including Sidhu. I was told he has sent his resignation," said the Chief Minister.

The feud escalated when Mr Sidhu went on Facebook live soon after the cabinet meet and said: "I cannot be taken for granted...I have been singled out in spite of collective responsibility."