Liberal Democrats will vote against Brexit and Scottish independence "at every opportunity we get", Willie Rennie has pledged.
At the party's manifesto launch in Edinburgh, the Scottish Lib Dem leader said voters could trust them to oppose both Brexit and independence whatever the outcome of the General Election.
The manifesto is committed to revoking Article 50 in the event of a Lib Dem majority or by working alongside other parties to get a People's Vote with the option to remain.
READ MORE: Sajid Javid warns Nicola Sturgeon over pact with Labour party
Arguing that to compromise on either position after the election would be a betrayal of their supporters, Mr Rennie said he had promised voters throughout the campaign that the Lib Dems would oppose Brexit and Scottish independence "whatever the circumstances".
Speaking at Murrayfield Ice Rink, Mr Rennie said: "We want to end the constitutional chaos and we will use our votes in Parliament at every opportunity to make it stop.
"I'm saying to people on the doorsteps, I'm saying to people in our leaflets, I'm saying to people in our manifesto - this is what you will get if you vote for us.
"I think that's very democratic and very straightforward.
"We can't go into an election saying we're going to one thing but if somebody else gets a certain number of seats we're going to do something different - that's not democracy."
Mr Rennie acknowledged the Lib Dems had been "condemned" for going into coalition with the Tories in 2010 but suggested there has been a rejuvenation in support for the party due to its steadfast opposition to Brexit since the EU referendum.
On the issue of trust, Mr Rennie said: "I think we are rebuilding that relationship with the voters because people see we are very clear with them, very straightforward and we will do what we say.
"No-one else is saying stop Brexit, stop independence.
"Labour are sitting on the fence and dithering on both, the Conservatives are wanting to add to the chaos with Brexit and the SNP don't seem to have learned any lessons from the last three and a half years that breaking up long-term economic partnerships is pretty difficult to do."
He added the party's focus was on the two constitutional issues of EU membership and keeping the union together - in addition to tackling climate change and improving mental health support - rather than the prospect of backing either a Labour or Tory Government.
"It's up to other parties to explain whether they are going to do coalitions together, but don't count on us," Mr Rennie said.
The party's Scottish manifesto also calls for a "federal-style" working arrangement between the UK's nations to co-ordinate tackling the climate crisis, giving the Scottish Government a greater role on drugs policy and backing safe consumption rooms in places such as Glasgow where drug-related deaths are "shockingly prevalent".