The Texas attorney general, Greg Abbott, has threatened to arrest international election monitors invited by liberal groups to observe the conduct of next month's presidential vote in states accused of attempting to disenfranchise minorities.

Abbott has written to the Organisation for Security and Cooperation in Europe warning that its monitors have no right to monitor the vote even though they have observed previous US elections.

"The OSCE's representatives are not authorized by Texas law to enter a polling place. It may be a criminal offence for OSCE's representatives to maintain a presence within 100 feet of a polling place's entrance," he said. "Failure to comply with these requirements could subject the OSCE's representatives to criminal prosecution for violating state law."

The OSCE is sending 44 observers to voting stations across the US at the request of various groups, including the NAACP and the American Civil Liberties Union, because of "an unprecedented and sophisticated level of coordination to restrict voting rights in our nation". These include attempts by several states, including Texas, to introduce voter identification laws and other measures blocked by federal courts which have ruled they were motivated by racial discrimination.

In his letter, Abbott glossed over the recent judgements striking down the Texas identification law and pointed to a supreme court ruling in a case involving another state.

"The OSCE may be entitled to its opinions about voter ID laws, but your opinion is legally irrelevant in the United States, where the supreme court has already determined that voter ID laws are constitutional," Abbott said.

The US routinely sends poll watchers to elections in foreign countries, particularly those where there are concerns about the fairness of the vote.

In television interviews, Abbott denounced the OSCE as an interfering foreign body even though the US is a founding member and it was invited by President George Bush's administration to monitor the 2004 and 2008 presidential elections in the US.

"If OSCE members want to learn more about our election processes so they can improve their own democratic systems, we welcome the opportunity to discuss the measures Texas has implemented to protect the integrity of elections," Abbott wrote. "However, groups and individuals from outside the United States are not allowed to influence or interfere with the election process in Texas. This state has robust election laws that were carefully crafted to protect the integrity of our election system. All persons – including persons connected with OSCE – are required to comply with these laws."

The OSCE responded later on Wednesday in a letter to the US secretary of state, Hillary Clinton, calling Abbott's threat "unacceptable" and noting that the organisation's Office for Democratic Institutions and Human Rights (ODIHR) has an agreement with the US permitting it to monitor elections.

"The United States, like all countries in the OSCE, has an obligation to invite ODIHR observers to observe its elections," it said. "The threat of criminal sanctions against OSCE/ODIHR observers is unacceptable."

A Florida congressman running for the Senate, Connie Mack, also waded into the debate, saying that reports the United Nations wants to send election monitors was an outrage. The OSCE was founded under the UN charter.

"The very idea that the United Nations - the world body dedicated to diminishing America's role in the world - would be allowed, if not encouraged, to install foreigners sympathetic to the likes of Castro, Chavez, Ahmadinejad, and Putin to oversee our elections is nothing short of disgusting," he told the Orlando Sentinal.

"The United Nations should be kicked off of American soil once and for all. And the American people should demand that the United Nations be stopped from 'monitoring' American elections. The only ones who should ever oversee American elections are Americans."