Sen. John McCain (R-Ariz.) called "unacceptable" on Thursday a decision by congressional appropriators to drop an amendment rushing the construction of the border fence with Mexico.

Conservatives expressed disappointment at the decision. They previously touted the amendment to the 2010 Homeland Security spending bill as a way to slow illegal immigration.

McCain tweeted his remark this morning:

approps drop mandate 2 finish border fence-unacceptable

A conference report issued yesterday dropped the provision. The amendment, which was presented by Sen. Jim DeMint (R-S.C.) garnered the support of most Republicans and 21 Democrats in the Senate, but was not included in the House bill.