What forced Shashi to resign?

PM is back from his foreign visit and before he landed at IGI Airport, Delhi; he knew he had to deal with a big problem. A problem which could have been smaller, had he banned his External Affairs Minister of State Mr. Shashi Tharoor from tweeting, when he first tweeted about travelling with cattle class. He was cursing himself for leaving him just with a warning then and not forcing him to delete his twitter account. He regretted the day when he failed to explain Shashi that Indian government is still formed with MPs selected by the population for whom twitter is just a bird noise and blackberry and apple are mere fruits. How come Shashi did not understand this simple fact that most of his 700K followers on twitter would not even go out of their cozy rooms to vote for him. These people are only good for signing online petitions in his favor, which are sadly not recognized and understood by major section of Indian population.

PM reached his office thinking about damage control. He was certain about one thing, "jo ek baar ho use galti kahte hain, lekin jo baar-baar ho use aadat kahte hain. galti ko sudharna aasan hota hai, lekin aadat badalna mushkil." He knew that this time he cannot leave Shashi with a warning. He had to take an action and the action had to be strict to set an example. While his mind was occupied with these thoughts, his personal phone rang. It was his wife. The conversation went something like this,
PM: I am so sorry. I promise it will not happen again.
Wife: Good. You dare not do this again. I am watching the TV and I see that idiot is just getting inside your office to meet you. Do the right thing this time.

His personal phone rang again as soon as he hung up. It was Sonia madam this time. His hands started shaking, because it was him who supported Shashi for the ministry despite madam's doubts. He answered the phone after waiting for good 30 seconds, which seemed like eternity to him. This is what they talked,
PM: Yes, madam. (trying to control his weight on his shaking feet)
Madam: What is this Manu? I told you keep him under control.
PM: Madam, I was out of country.
Madam: Then you better stop going out of country. Send only Krishna to all such trips. Isn't that the reason we appointed him the external affairs minister? You better keep check on these internal affairs.
PM: Don't worry madam. I will find a solution.
Madam: You better.

He hung up the phone. A peon entered the office, while he was wiping sweat off his face. "Tharoor sahab aaye hain, bade pareshan dikh rahe hain", the peon said. "Uski wajah se to main pareshan hun. Ghar me biwi bolti hai foreign vacation ka plan kyon cancel kiya aur wohan madam bolti hain internal affairs samhalo. Bhejo andar, aaj uski khair nahi", he replied.

Shashi entered the office holding a neatly folded paper in his left hand and his cellphone on the other. "Sir, I have prepared a statement explaining my situation in this entire episode", Shashi said looking at his cellphone following Lalit Modi's tweets. "I wonder, why you had to come with an statement, when you could have tweeted me the same", PM said fuming with anger. Shashi hurriedly kept his cellphone in his pocket sensing the anger in PM's voice.

PM walked to Shashi, held him from behind his neck and looked into his eyes. "What is this Shashi? Every time I go out of country, you do something that forces me to cut short my trip." he said in a soft voice, as if hushing it in his ear. "I cannot have a nice quiet foreign vacation with my family because of you. Madam is asking me to concentrate on internal affairs first and I have decided to start from my home. That is the reason I am planning a foreign vacation with your bhabhiji to compensate for all the foreign trips those were cut short because of your continuous careless tweeting habit." he continued. "I am sorry sir, but this Modi fella.." Shashi apologized. "We were struggling with one Modi already and you have given us another Modi to fight with. Were you out of your mind? I think, we will handle this Modi. PC has been working on it for over a year now and I am sure he will come up with something. He sure is 100 times smarter than you are." he said looking away from Shashi.

When PM looked back at Shashi, he looked calmer. "You must resign Shashi, I cannot afford to cut short my next trip and anger your bhabhiji and madamji. You must go Shashi," he said.