A person elected to both Houses of Parliament must intimate which House he wishes to serve in within:

If a person is elected to both the Lok Sabha and the Rajya Sabha, he must inform the authorities within 10 days of the later election which House he wishes to serve in. If he does not do so, his seat in the Rajya Sabha becomes vacant.

Constitutional basis:

• Article 101(1) says that no person can be a member of both Houses of Parliament.
• Parliament has made provision for vacating the seat of a person elected to both Houses through the Representation of the People Act, 1951.

Detailed rules:

• If a sitting member of one House is elected to the other House, his seat in the first House becomes vacant on the date of his election to the other House.
• If a person is elected to both Houses at the same time, he must choose within 10 days; otherwise, his Rajya Sabha seat falls vacant.

Membership of Parliament and a state legislature:

Article 101(2) says that a person cannot be a member of both Parliament and a state legislature.

Under the Prohibition of Simultaneous Membership Rules, 1950, if a person is elected to both, his seat in Parliament becomes vacant unless he resigns his seat in the state legislature within 14 days of the publication of the result.

Elected from two constituencies:

If a person is elected from two constituencies to the same House, he must resign one of them within 14 days; otherwise, both seats become vacant.

Other ways a seat falls vacant:

• Resignation, disqualification, absence without permission for 60 days, election being declared void, and expulsion.
• Disqualification under the Tenth Schedule for defection.
• Vacation of seat on becoming President, Vice-President or Governor.

State legislatures:

Article 190 contains similar rules for members of state legislatures.

Why not the other options?

• ✗14 days is the period for resigning from a state legislature or a second constituency.
• ✗7 days and 30 days are not the periods laid down.