Joint sitting is an extraordinary machinery provided by the Constitution to resolve a deadlock between the two Houses over the passage of a bill. A deadlock is deemed to have taken place under any one of the following three situations after a bill has been passed by one House and transmitted to the other House:

I) if the bill is rejected by the other House;

II) if the Houses have finally disagreed as to the amendments to be made in the bill; or

III) if more than six months have elapsed from the date of the receipt of the bill by the other House without the bill being passed by it.

In the three scenarios described above, the president has the authority to call both Houses together for a joint session to deliberate and vote on the bill. It should be underlined that the provision of joint sitting only applies to ordinary bills or financial bills, not money bills or Constitutional amendment bills. The Lok Sabha has overriding powers in the event of a money bill, whereas a Constitutional amendment bill must be enacted by each House individually.

                No account can be taken of any period during which the other House (to which the bill has been referred) is prorogued or adjourned for more than four consecutive days when calculating the six-month period.

No joint sitting can be called if the bill (in dispute) has already lapsed due to the dissolution of the Lok Sabha. The joint sitting, however, can take place if the Lok Sabha is dissolved after the President has advised him of his intention to call such a meeting (as the bill does not lapse in this case). After the President announces his intention to call a joint session of the two Houses, neither House can take action on the measure.

In the absence of the Speaker of Lok Sabha, the Deputy Speaker preside over a combined session of the two Houses. If both the Deputy Speaker and the Chairman of the Rajya Sabha are absent from a combined session, the Deputy Chairman of the Rajya Sabha preside. If he is also absent, the meeting is presided over by whoever the members present at the joint sitting decide. Because he is not a member of either House of Parliament, it is obvious that the Chairman of Rajya Sabha does not preside over a joint session.

A quorum for a joint sitting is one-tenth of the total number of members in both Houses. The combined session is governed by Lok Sabha Rules of Procedure rather than Rajya Sabha Rules of Procedure.

The bill is judged to have been passed by both Houses if it is passed by a majority of the total number of members of both Houses present and voting in the joint session. In a joint sitting, the Lok Sabha with the most members usually wins.

The Constitution has specified that at a joint sitting, new amendments to the bill cannot be proposed except in two cases:

I) those amendments that have caused final disagreement between the Houses; and

II) those amendments that might have become necessary due to the delay in the passage of the bill.

Since 1950, the provision regarding the joint sitting of the two Houses has been invoked only thrice. The bills that have been passed at joint sittings are:

I) Dowry Prohibition Bill, 1960

II) Banking Service Commission (Repeal) Bill, 1977

III) Prevention of Terrorism Bill, 2002.