King Charles has been allowed to vet and potentially lobby for changes to emergency legislation to freeze rents in Scotland because the measures could affect tenants on his private Highland estate at Balmoral. A bill to stop landlords unjustifiably raising rents for the next six months because of the cost of living crisis is being rushed through the Scottish parliament this week. The King’s involvement, under rules known in Scotland as crown consent, can be revealed after the rules at Holyrood were changed following a Guardian investigation into the monarch’s power to influence and amend the UK’s laws. The Guardian revealed last year that ministers in Edinburgh had allowed Queen Elizabeth to vet at least 67 pieces of legislation that affected her personal property and public powers under the arcane custom, inherited from Westminster. A Scottish government memo revealed it was “almost certain” draft laws had been secretly changed to secure the Queen’s approval. There has been growing criticism that the unelected monarch is able to use the secretive mechanism to secure changes to proposed laws without the public being informed; an allegation rejected by the royal family. In response, Holyrood’s presiding officer, Alison Johnstone, told the Scottish government it now had to inform parliament as soon as a new bill was tabled whether the monarch had been allowed to see it first. Previously, ministers would only tell MSPs at the final stages of a bill’s parliamentary scrutiny that the monarch had been allowed to secretly vet it. Ministers have also refused to release letters from the late Queen’s solicitors lobbying for changes on her behalf. The cost of living (tenant protection) Scotland bill is the first piece of draft legislation affected by Johnstone’s ruling and is the first at Holyrood to be vetted by the King. In a further development, Scottish ministers said on Monday they would also start explaining why crown consent was required for new bills. Previously, such explanations have not been made public. In an announcement a few hours before the rent control bill was published, George Adam, the minister for parliamentary business, said ministers would now explain how a bill applied to the royal family’s personal and official interests, and why crown consent was needed. What the government does not say is whether any changes were made to the draft bill at the King’s request and, if so, what those were. The government had previously rejected opposition demands for greater transparency about the monarch’s ability to secretly lobby ministers to change legislation, and the monarch’s rights to scrutinise legislation before MSPs. A policy memorandum published with the draft bill states: “Crown consent will be required because it is considered that the provisions in the bill affecting private residential tenancies could affect residential tenancies on His Majesty’s private estates and those on land forming part of the Scottish crown estate.” The SCE manages land and property which were previously held by the monarch, but its profits are used by the Scottish government. The Scottish Liberal Democrats, who helped reveal last year the extent to which crown consent applies in Scotland, said Adam’s measures “barely scratch the surface”. Alex Cole-Hamilton, the Scottish Lib Dem leader, said: “This policy would ensure we still remain utterly in the dark. The Scottish government should instead specifically list any changes made to legislation at the request of the King’s lawyers when it arrives at and goes through parliament. “Everyone deserves to know how their laws are being made because transparency and scrutiny are pillars of our democracy.” Anas Sarwar, the Scottish Labour leader, said if his party won power at Holyrood it would introduce laws requiring ministers to publish correspondence on the King’s lobbying. “I think people would expect any democratic system, a system designed for the people and in a representative parliamentary democracy, for these issues all to be out in the open for people to know how decisions are made, why decisions are made and where suggested amendments have come from,” Sarwar said. As an interim measure, Labour said it hoped to expand Scotland’s freedom of information legislation to include correspondence by the King’s lawyers. A private member’s bill being tabled by Katy Clark, a Scottish Labour MSP, aims to update Holyrood’s 20-year-old freedom of information regulations. Sarwar’s pledge represents the most radical proposal in the UK to open up the arcane consent mechanism. More than 1,000 laws were vetted by the late Queen during her reign before they were passed by the Westminster parliament. The UK government will simply state consent has been applied, but provide no further information. A spokesperson for the King at Buckingham palace said: “King’s consent has been requested for this bill and will be processed in the usual way. Consent is provided on the advice of government in line with convention.”