A string of new legal cases are going to make it tough for the U.K. to formally exit the European Union.

The British public voted with a slim majority to leave the European Union last month. But at least five legal challenges have cropped up that could slow, halt or complicate the so-called "Brexit" process.

Here's a rundown of the different cases:

Maitland Chambers

Law firm Maitland Chambers will be the first to present a lawsuit in court to challenge the legality of the government's plan to exit the European Union.

An initial hearing is set for July 19.

Maitland Chambers' senior barrister Dominic Chambers says that, contrary to popular belief, the incoming U.K. prime minister -- Theresa May -- does not have the legal authority to trigger the nation's formal exit from the European Union.

Instead, all members of Parliament must first vote on this issue, according to rules on parliamentary sovereignty. An exit from the EU can only happen once members of Parliament approve the move, though many do not think it's in the nation's best interest.

The firm is bringing the case forward on behalf of a concerned citizen, a London-based hairdresser, Deir Dos Santos.

Chambers told CNNMoney that his client's case was not designed to block Brexit.

"He wants to ensure that the rule of law is followed," he said.

It's worth noting that the result of the referendum was not legally binding, but only advisory in nature.

Mishcon de Reya

Top London law firm Mishcon de Reya is preparing a similar legal action to ensure U.K. lawmakers debate and vote on Britain's exit from the European Union before the country embarks on its path out of the bloc.

Mishcon de Reya said it had been corresponding with government lawyers since June 27 and it would go to court if necessary.

The law firm argues that members of Parliament must be given a chance to vote and approve Brexit. Otherwise, the move isn't legal.

Mishcon de Reya said it was representing "a group of concerned British citizens."

1,000+ barristers

More than 1,000 lawyers across the U.K. have signed a letter to remind the prime minister and members of Parliament that while the results of the referendum must be acknowledged, they are not legally binding.

They are calling on members of Parliament to vote on leaving the EU before making a final decision.

"The Parliamentary vote should take place with a greater understanding as to the economic consequences of Brexit, as businesses and investors in the U.K. start to react to the outcome of the referendum," the lawyers said in their letter.

However, no formal legal action is expected to follow this letter.

The expat challenge

British citizen and World War II veteran Harry Shindler, 94, argues that hundreds of thousands of British citizens living abroad were denied the right to vote in the referendum, which should nullify the referendum results.

Anyone living outside the U.K. for over 15 years was denied a referendum vote.

Shindler, who has been living in Italy since the early 1980s, said the fact that he was denied a vote was arbitrary and undemocratic.

"There must be democracy. And at the moment, this Brexit thing is not democratic," he told CNNMoney.

Shindler has exhausted his legal options in U.K. courts, but his challenge is now being heard by the United Nations Commission on Human Rights, he said.

The U.K. government has already rejected a petition calling for a second referendum, signed by more than 4 million people.

Targeting Leave campaigners

Barrister Anthony Eskander at the firm Church Court Chambers in London, said he is considering assisting clients with a criminal case against the individuals who led the campaign to leave the EU, asserting that they misled voters with broken promises.

He expects these individuals, including former London mayor Boris Johnson, could be found guilty of misconduct in public office, which would be a criminal offense.

However, the case could take months or years to wind through the courts and would not necessarily stop the government from triggering an exit from the European Union.

Regardless, he told CNNMoney the case would still be worth pursuing because campaigners should be held accountable for their "propaganda".