WASHINGTON: A leading Republican presidential candidate has called for suspending the issuance of H-1B visa for six months to investigate abuses against the most sought work visa by Indian IT professionals."In order to strengthen our immigration system, protect national security and better serve American workers, we must suspend the issuance of all H-1B visas for 180 days to complete a comprehensive investigation and audit of pervasive allegations of abuse of the program," said Republican presidential candidate Ted Cruz as he rolled out his immigration reform plan."New allegations detail appalling abuses of the H-1B visa program - a program meant to create American jobs and spur economic growth. I will suspend the program for 180 days to investigate abuses," said Cruz whose popularity ratings in the last few weeks have increased nationwide.Interestingly, as a Senator from Texas, Cruz had backed quintupling the number of H-1B visas. Cruz also called for halting increases in legal immigration so long as American unemployment remains unacceptably high."The purpose of legal immigration should be to grow the economy, not to displace American workers. Under no circumstances should legal immigration levels be adjusted upwards so long as work-force participation rates remain below historical averages," he said.Cruz sought to end birthright citizenship. "Birthright citizenship was not intended to legalise the children of people who are breaking the law by entering and staying in the country illegally. I will take steps to pass legislation or a constitutional amendment to end it," Cruz said.In his speech in Orlando, Florida Cruz said if elected as the president he will suspend the H-1B program for 180 days to investigate abuses and enact fundamental reforms of this program to ensure that it protects American workers."A Cruz administration will enforce existing protections for American workers and amend the H-1B visa program to fulfill its original purpose," he said.Calling for creating a "layoff cool-off" period for all H-1B visa applications, he said companies must wait one or two years between laying off a worker and bringing in any H-1B foreign workers to ensure that the program is not used to displace American workers.Observing that the recent lack of federal oversight of the H-1B visa program has fueled a cottage industry of diploma mills, he said, foreign academic institutions must meet minimum accreditation standards at least as stringent as those imposed on American universities in order to qualify for the advanced-degree requirement.Under his plan, Cruz said companies will provide sworn statements and documentation that detail their efforts to hire Americans before requesting foreign workers through the H-1B visa program.Individuals who make false statements in these affidavits will be subject to perjury charges, he said.