After Lok Sabha elections are over, the leader of the party having won absolute majority (more than 50% of Lok Sabha seats) is invited by the President to form government. The leader of this majority party is appointed as the Prime Minister and other Ministers are appointed on the advice of the Prime Minister.
Thus, it is the Prime Minister who has the prerogative of appointing Ministers. He not only selects Ministers. He also decides which portfolio a Minister will handle. Thus selection of Ministers and allocation of portfolios are done by the Prime Minister.
If, in any General Elections, no single party is able to win absolute majority, the leader of the single largest party is normally given a chance to form government with the support of some other party or parties. If a coalition of party’s claims to enjoy majority in the Lok Sabha, then the leader of the coalition may also be invited to prove his claim in such a situation.
Where no single political party has won necessary majority in the Lok Sabha election, either the leader of the largest party or the leader of a coalition claiming majority may be invited by the President to form government and to prove his majority in the Lok Sabha within certain days. If his government fails to get majority support in the Lok Sabha, the leader of another party or coalition may be invited to form government or the Lok Sabha may be dissolved and fresh elections ordered though the process would prove to be very expensive and time-and-energy consuming.
A member of either House of Parliament can be appointed as a Minister at the centre. There is no constitutional bar even on a nominated member of Rajya Sabha being appointed as a Minister. However, a convention has developed against appointing these MPs as Ministers. Selection of Ministers is the discretion of the Prime Minister. But he is influenced by certain factors in selecting Ministers. He seeks to ensure that various regions/ states, minority groups, other disadvantaged groups and other sections of the population like young and woman are represented in the Council of Ministers.
He also tries to include in the ministry the representatives of various factions of his party. Needless to say, in appointment of Ministers, loyalty is rewarded. The Prime Minister will be careful to select some Ministers who are his confidants or who are loyal to the party high command or those who are otherwise powerful in the party. A good example of such leaders is Mrs. Sonia Gandhi who is the high command of congress party.
One who is not an MP may also be appointed as a Minister. But such a Minister has to be a Member of Parliament within six months from the date of his appointment as a Minister. Otherwise, he will cease to be a Minister after the expiry of this six-month period. This provision has been included in the constitution to enable the Prime Minister to bring to his ministry talented and capable people who might have lost elections or who might not have contested elections at all.
When a nonmember of Parliament is appointed as a Minister, the ruling party normally helps him in being elected as a member of Rajya Sabha within six months. Dr. Manmohan Singh was not a Member of Parliament when he was appointed as the Finance Minister in the Rao Government by Narasimha Rao. But within 6 months, Dr. Singh was elected as a member of the Rajya Sabha. Sivraj Patil, the Home Minister in the first Manmohan Singh Government, was not an MP at the time of his appointment. His party (Congress) was sure of getting him elected to the Rajya Sabha within six months.
In the UPA governments, first and second most ministers from congress party were/ are loyal to Mrs. Sonia Gandhi. Similarly, in the NDA governments headed by A. B. Vajpayee, many BJP ministers had the blessing of RSS.