A senior lawyer has warned of state overreach if the SNP's proposed ban on "conversion practices" in Scotland gets the go-ahead.
Under the SNP's plans, parents who refuse to allow their children to change gender face up to seven years in jail.
The SNP wants to criminalise actions actions designed to "change or suppress" an individual's gender identity, and those that are deemed "coercive" or "controlling", even where the intention is to help or protect the person.
The Scottish government is consulting on its proposals until 2 April.
Critics have warned that they will unfairly criminalise pastors and loving parents, as well as counsellors who do not take an affirmative approach.
Aidan O'Neill KC outlined his concerns in a 46-page legal opinion provided to The Christian Institute in which he described the legislation as "ill-thought out, confused and confusing, and fundamentally illiberal in intent and effect".
"This is perhaps best described as 'jellyfish legislation'," he said.
"The concepts it uses are impossible to grasp; its limits are wholly undefined; it contains a sting in the tail in the form of criminal sanction of up to seven years and unlimited fines; and thus it will have an undoubted and intended effect of dissuading persons from ever even entering the now murky waters of what may or may not constitute unlawful 'conversion practices'."
He warned that the proposals would allow the State to encroach on private family life and undermine religious freedom.
"The proposals which the Scottish Government has consulted on would, if passed into law, effect radical changes in the current law. They will also involve a marked intrusion and expansion in the powers of the State into the private realm of families, and over the expression of orthodox religious teaching by faith groups," he said.
The Christian Institute's Deputy Director, Simon Calvert, said it was "outrageous" that pastors and ordinary mums and dads are facing criminalisation.
"This is another example of the Scottish Government asking Holyrood to exceed its powers and impose draconian legislation on the people. If this deeply flawed law is passed it will be challenged all the way to the Supreme Court if necessary," he said.
He added, "They've spent over two years drafting this. It's time to admit that no-one can define what conversion therapy is, let alone how to criminalise it."
The Christian Institute has said it will take legal action if the ban is implemented. Eight years ago, the organisation successfully challenged the Scottish government at the Supreme Court over its controversial 'Named Person' scheme, dubbed a 'snooper's charter' by critics. The Scottish government later scrapped the proposals.
