Scottish ministers are rushing through dozens of urgent legislative changes in an last-minute effort to protect Scottish businesses and consumers from a no-deal Brexit.

The Scottish government has identified 36 legislative measures it believes are critical and must be in place before 29 March to ensure devolved areas such as farming, fisheries, food safety, the environment, animal welfare and forestry are protected if the UK crashes out of the EU.

Officials and party business managers at Holyrood are preparing to order late parliamentary sittings, cancelling non-essential debates or votes and holding extra committee hearings to sit at the same time as parliament is in session to help cope with the surge in work.

Mike Russell, Scotland’s secretary for constitutional affairs, said his government had a duty to prepare for Brexit and was redeploying staff to do so.

“We share the frustrations of businesses, communities and individuals across the country that we are being forced to prepare for a range of uncertain and unknown scenarios, diverting resources away from other areas, as we leave the EU against the wishes of the majority of Scots,” he said.

The former Scottish Labour leader Kezia Dugdale has estimated the Scottish government’s preparations for Brexit will cost nearly £100m by April 2020, including planning for a no-deal scenario.

“The future total figure could be considerably greater, this is all money that could have been invested in our struggling NHS, schools or rail services,” Dugdale said.

Quitting the EU means hundreds of pieces of legislation need to be amended to ensure laws in force across the UK and devolved nations are updated to guarantee the same legal standards and protections in place now are in force after Brexit.

Most of those changes are being pushed through Westminster, Holyrood and the Welsh assembly using statutory instruments, a type of secondary legislation that can be introduced without passing a new act. In some cases changes to different laws will be bundled up into one statutory instrument, and in some high-priority cases they require a parliamentary vote to agree them.

Despite last year’s legal battle between the UK and Scottish governments over Holyrood’s emergency Brexit legislation, known as the continuity bill, Scottish and UK civil servants have agreed to share the workload in updating the affected laws.

Whitehall has already written and overseen a large majority of the statutory instruments that affect Scottish legislation before sending those to Holyrood for formal approval under UK-wide “common frameworks”.

By 23 January, 105 UK-wide statutory instruments had been passed by MSPs, covering areas such as nuclear safety, genetically modified foods, tobacco controls, greenhouse gas emissions trading, gender equality, renewable energy, organ transplants and food safety.

However, that leaves scores of changes for Scottish ministers to oversee using Scottish statutory instruments (SSIs). In addition to the 36 critical measures that Holyrood needs to process before 29 March, dozens of other SSIs will need to be approved after Brexit day.

Scottish ministers are cautious about disclosing the titles of these measures before they are tabled, citing the need to observe the protocol that parliament should be told first.

Russell is meanwhile in talks with opposition parties about when and whether to table an amended continuity bill. The UK supreme court ruled in December that the continuity bill was unlawful, in large part because the UK government altered Holyrood’s legal powers after it had been introduced, stopping it being enacted in its current form.

He would not be drawn on what would happen next, but legal sources say they believe its fate hangs on what happens with Brexit at Westminster.

Opposition MSPs suspect Russell plans to table new farming and fisheries bills after Brexit, which could cause friction with UK legislation being proposed by Michael Gove, the environment secretary.