Shimla, Aug 19 - 'I am sad and regretful,' Jaswant Singh said Wednesday shortly after getting a phone call from Bharatiya Janata Party (BJP) president Rajnath Singh that he had been expelled from the primary membership of the party.

'I am sad and regretful. There are many reasons. I will not go into details for everything but will say that it would have been better if I had been given the news in person instead of over the phone,' he told reporters.

Jaswant Singh, who has written a book on Pakistan founder Mohammed Ali Jinnah, said he got a call at 1 p.m. from Rajnath Singh.

'If this was the decision, it would have been better if I had been told in Delhi not to come to Shimla,' he said.

'I have been a member of the BJP since it was formed (in 1980),' he said.

'I am worried and sad that just one book has led to my expulsion,' he added, wondering what would happen if 'soch, vichar and chintan' (thinking and introspection) stopped in Indian politics.