Ruth Davidson has said people feel mis-sold over Brexit and that it is "astonishing" there is a possibility that the Prime Minister may not abide by the law and ask for an Article 50 extension if no deal is reached with the European Union.
Ms Davidson, who stood down as leader of the Scottish Conservatives two months ago, also urged MPs to back a deal if one is put before Parliament.
The Edinburgh Central MSP, who helped launched a new fundraising campaign for the mine-clearing charity, the HALO Trust, also revealed she would be interested in working in international aid when she stands down from Parliament at the 2021 elections.
Ms Davidson was asked about the Brexit minefield, and whether she believed Boris Johnson would abide by the Benn Act. "I think it's astonishing we're even asking the question," she said..
The Court of Session today said that it would reconvene later in October if Mr Johnson failed to strike a deal with the EU and also failed to then ask for a Brexit extension as laid down by the law passed by MPs just before he unlawfully prorogued Parliament.
She added: "Governments have some basic, basic tenets which never should even need to be spoken, of which respecting, upholding and promoting the rule of law is one of them. Defence of the realm is the second, and promoting community cohesion is the third, to make sure we're a harmonious country, and from that flows all the other things governments should do. This is what governments of grown up western democracies do."
Refusing to make a prediction on Brexit, as she had previously been "wrong", she added: "In terms of the position I've always adopted, even though my side lost, I believe loser's consent is important, so I think it's important that if a decision has been put to the country you've got to listen to what the country comes back with, so I think Brexit will happen.
"However, part of that Brexit campaign was we were told there would be a logical sequence to these things, international agreements, a velvet divorce if you like, and the idea there won't be those under-pinning agreements has people feeling that they were mis-sold and concerned for the future and I agree with them."
Ms Davidson said that she would still be happy with Theresa May's deal if it was brought back to Westminster for a fourth time, or a new deal from Mr Johnson as "it's not likely to be anything wildly different".
She added: "I think politicians from all parties in the House of Commons need to look at what the options are, and back that deal. It might not be all they wanted and will require compromise but let's not make perfect the enemy of the good, because the other option is falling out without a deal that's not in anyone's interests."
She also denied that at First Minister's Questions last week she expressed her disapproval of interim leader Jackson Carlaw's approach to Brexit, which backed that of Mr Johnson. Laughing, she said: "It's not unusual for me to look thunderous when I'm not smiling, even if I'm trying to look neutral, obviously that didn't come across."
Asked if she believed Mr Carlaw should be her permanent replacement, she said: "My predecessor and her predecessor stayed out of leadership contests, they didn't declare who they were supporting, and I'm going to sit above this one too and see the candidates who come forward. We have strength and depth in our ranks, and I'll get behind who the new leader is."
Ms Davidson was speaking at ESMS, one of Edinburgh's private schools, where the HALO Trust was giving pupils a hands-on experience of using detectors in a dummy mine field in the school grounds, to show the dangers faced by children in Zimbabwe as they walk to school.
She has previously been to Afghanistan with the charity, which is the largest non-government organisation in Scotland, with 9000 staff in 26 countries around the world. It has plans to clear 105,600 square metres of land in Zimbabwe over the next 12 months, to help more than 3,000 people get access to safe land to grow food and give safe access to school.
Its new Breaking Boundaries fundraising campaign is supported by the UK government which has pledged to double donations made by the public up to a total of £2 million.
And she said that the work of the charity, and of international aid, was attractive to her in terms of a post-political career. She has recently said she was not likely to stand at the next Holyrood elections.
"I would absolutely love to be more involved in some of the work that goes on overseas," she said. "The UK has an enormous, amazing story to tell in terms of its aid development work around the world. We are the single largest educator of girls anywhere in the world, in countries where it's not traditional for girls to have schooling.
"I've always had an interest in international development. I would love to get into, but as it's overseas, probably not while my child is of school age but thereafter yes, it's something I'd love to do."
She added: "I have been a supporter for a long time, and helped them to encourage the UK government to increase support for clearing landmines around the world, to £100m and bring in help from other countries.
"They want to see a landmine free world, and it's achievable. Most armies don't use landmines anymore, but they can stay in the ground for 30 years or more and still kill people, so it's about how do we clear them?
"Clearing landmines helps children get education so it's about the future of a country, it stops large swathes of a country being utterly unusable for food, for building, for retail, for all the things we take for granted, if you can return land to the country you have fewer people without income, particularly men of the 15-30 age group who can be easily recruited in some of these countries to fight against the west, so it helps in our anti-terrorism goals, so it's a virtuous circle."
Recalling her trip last year to Helmand, she said she "stupidly" flew out on the first day her embryo was in place. She gave birth to her, and partner Jen's son, Finn, last October.
"I was under huge orders from my partner to behave myself, so it was a very worrying time, but it was the way the timings worked and they [HALO] had spent a lot of money to get me out there so I didn't want to withdraw.
"In Helmand they not only train the de-miners, they also train women to have jobs to do surveys of villages, to do preparatory and post removal work, so they have incomes. And they're expanding what they do into making other weaponry safe, handing in RPGs and other rifles."