The number of people attempting to illegally enter the country appears to have spiked this year as Congress debates granting legal status to the nation’s estimated 11 million illegal immigrants.

Customs and Border Protection (CBP) chief Michael Fisher told a Senate panel Tuesday that apprehensions of people illegally crossing the southern border into the United States have increased by 13 percent this year.

The jump comes after nearly seven years in which apprehensions have declined.

Sen. John McCainJohn Sidney McCainMark Kelly releases Spanish ad featuring Rep. Gallego More than 300 military family members endorse Biden Jennifer Lawrence says until Trump she was 'a little Republican' MORE (R-Ariz.) attributed the increase to the possible passage of immigration reform legislation, and to sequestration budget cuts that have reduced CBP’s ability to patrol the border.

“The economy has something to do with people’s desire to come across the border,” McCain said at a Senate Homeland Security and Governmental Affairs Committee hearing on the state of the border’s security.

“And part of it is that word has gotten south that sequestration has reduced our ability to surveil, and there may be comprehensive immigration reform,” he said.

Total apprehensions increased last year from about 340,000 in fiscal 2011 to about 364,000 in fiscal 2012, according to CBP’s data. But this is about a quarter of the number of apprehensions reported in 2005, when CBP caught nearly 1.2 million people attempting to cross the into the country illegally.

Homeland Security Secretary Janet Napolitano and other federal law enforcement officials have pointed to the decreasing apprehension numbers as a sign that border security has increased in recent years, causing less people to attempt to cross into the country. The slow economy over the past several years is another reason why apprehensions may have declined.

The ability of the federal government to secure the border is at the center of the debate over immigration legislation, which McCain and seven other senators helped craft.

Though the Obama administration has repeatedly testified that the border has never been so secure, many Republicans are wary of supporting a bill that does not take steps to tighten security measures along the U.S.-Mexico border.

Department of Homeland Security Assistant Secretary for Policy David Heyman said he’s confident border security will be strengthened by the Senate bill, which includes a new employment verification and worksite enforcement process. It also grants more money and technology to border security efforts.

“If you put all of that together, our ability to have better control of the borders will also improve,” said Heyman. “We’re confident that it’s the right formula.”