The Scottish parliament is to consider changes to the way it handles new legislation that has been amended to protect the Queen’s interests. A Holyrood spokesperson said officials could change the rules to make it much clearer that new bills had been altered, after the Guardian revealed at least 67 pieces of legislation had been vetted by the Queen’s officials. In a further development, Humza Yousaf, the Scottish health secretary, said the Scottish government could ask the Queen for permission to publish her correspondence if there was sufficient public and political demand to do so. While some Scottish National party politicians and activists are openly furious about the extent of royal influence in Scotland, Yousaf said it would be done only if the Queen’s officials agreed. “We would have to obviously speak to the royal household about that, there would be implications in that respect,” the minister told BBC Scotland. “But of course if that’s something parliament, the public want us to do, to examine and explore that, then we will examine and explore that.” It is unlikely the Queen’s officials would agree to that level of transparency, despite a backlash following the Guardian’s disclosure earlier this week that Scottish ministers agreed to amend a green energy bill after lobbying from her lawyers. The Queen vigorously protects a longstanding convention that her communications with government ministers are kept secret. So, too, does the Scottish government: it has repeatedly refused to publish royal correspondence, claiming it would damage the public interest to do so, and introduced strict rules on releasing information affecting the royal family. The Scottish government changed a bill in February to prevent the Queen’s private estate, Balmoral, from being subject to compulsory purchase powers to allow low-carbon heating pipe networks to be installed across her land. MSPs say they were not told that change was made after her Scottish lawyer secretly intervened. The Scottish government has since refused to release that correspondence, saying it had to protect the Queen’s “appearance of political neutrality”. Investigations by the Guardian suggest a number of other pieces of Holyrood legislation have been changed after interventions by the Queen’s lawyers and officials under a process known in Scotland as crown consent. It has been heavily used at Westminster, under a convention known there as Queen’s consent. More than 1,000 bills have been subject to the procedure during her 68-year reign. Under this opaque convention, ministers send draft laws to the Queen so she can check whether they affect her private interests or constitutional powers. Ministers are required to get her approval for those laws before they can be passed by elected politicians. A Scottish parliament spokesperson said applying crown consent was the responsibility of ministers but Holyrood would review its handling of such bills. “The parliament will give consideration to how to make the signifying of crown consent more transparent,” she said. It is thought that could involve a new requirement that ministers or the parliament issue a declaration before a bill is debated that it has been amended in consultation with the Queen’s officials or lawyers. Holyrood already requires a public statement to be made by the presiding officer and the government that new bills do not overstep its powers as a devolved parliament. Supporters of the change say it would allow MSPs to question ministers about the arguments in favour of the change, and increase the chances it could be rejected by MSPs. The Scottish Liberal Democrats, which uncovered the Queen’s intervention with the heat networks bill, have tabled a series of questions challenging the policy and asking Nicola Sturgeon’s government to name all the acts which have been affected by crown consent. The Lib Dems have asked ministers voluntarily to publish all the correspondence from the Queen’s solicitors and officials when the procedure is used in future. They are also appealing to the Scottish information commissioner, who oversees freedom of information laws, to seek the full disclosure of all the Queen’s correspondence on the heat networks bill. The Scottish government was heavily criticised in 2016 by a previous information commissioner, Rosemary Agnew, and opposition MSPs for issuing “misleading” internal rules on handling royal correspondence. Agnew said its rules went far beyond the legal requirements of the Freedom of Information (Scotland) Act 2002. In particular, she criticised Scottish ministers for insisting the royal household was automatically told when someone applied for royal correspondence to be released.