Legislative Branch Appropriations Act, 1991

Legislative Branch Appropriations Act, 1991 - Title I: Congressional Operations - Congressional Operations Appropriations Act, 1991 - Appropriates funds for FY 1991 for the operations of the Senate. Sets forth administrative provisions for the use of such funds. Appropriates funds for: (1) joint items of the House and Senate; (2) the Office of Technology Assessment; (3) the Congressional Budget Office; (4) the Office of the Architect of the Capitol; (5) the Congressional Research Service of the Library of Congress; and (6) congressional printing and binding at the Government Printing Office.

Empowers U.S. Capitol Police to make arrests off Capitol grounds in certain circumstances.

Title II: Other Agencies - Appropriates funds for: (1) the Botanic Garden; (2) the Library of Congress; (3) the Architect of the Capitol; (4) the Copyright Royalty Tribunal; (5) the Government Printing Office; and (6) the General Accounting Office. Sets forth limitations on the use of such funds.

Title III: General Provisions - Sets forth various specified requirements for and prohibitions against or limitations on the use of appropriations.

Directs the Architect of the Capitol to develop an overall telecommunications plan for the other agencies of the legislative branch that will be compatible with current plans of the House and the Senate.

Authorizes legislative branch agencies to use telecommunications systems and services provided by the Architect of the Capitol, the House, or the Senate under a specified plan if such systems and services have been: (1) acquired competitively; and (2) determined to at least equal in quality to, and not greater in cost than, the systems and services known as "FTS2000."

Amends Federal law to remove the disbursement authority of the Botanic Garden from the Library of Congress.

Requires Federal departments, agencies, or instrumentalities to have a policy designed to ensure that all of its workplaces are drug-free.

Amends the John C. Stennis Center for Public Service Training and Development Act with respect to the Center's use of income from investments.

Repeals the limit applicable to Senators on postal patron mailings.

Authorizes the President pro tempore of the Senate to adjust the pay to maintain the same pay relationships that existed on December 31, 1986, between personnel and Senators and between positions.

Prohibits Members of the House of Representatives from sending mass mailings for delivery outside their Districts.

Amends Federal law to prohibit additional mass mailings during a fiscal year if the Postal Service determines that postage costs appropriations for franked mail have been exhausted.

Requires FY 1991 pay raises to be absorbed within the levels appropriated in this Act.