As new powers over tax and welfare are devolved, the Scottish Conservative leader used her address to call on all parties to remember that Scotland does not exist "in a vacuum".
She warned that Holyrood “has an unhealthy obsession with gazing at its own navel" over constitutional issues.
She added: "As the parliament prepares to take on huge new responsibilities, it's time to remember that there is a world outside the Scottish Parliament – and it's a world which will be watching us ever more closely."
The speech was given at the Edinburgh International Conference Centre this evening at the annual dinner of the FSB's East of Scotland region.
Scottish Conservative leader Ruth Davidson said:
"We are less than six months away from the Scottish Parliament elections. What is clear is that the coming Holyrood election will be the most important of the post-devolution era.
"That's not just the usual politician hype. It's a plain fact.
"With massive new tax and welfare powers likely to be devolved to Holyrood the year after next, the next Parliament will decide the amount of income tax you pay, and the kind of welfare state we want.
"Scottish politics is about to be transformed from a spending competition within a fixed envelope, to a proper debate about our priorities.
"I supported this change, and indeed it was the Scottish Conservatives’ plan for further devolution which was the basis for much of the Smith Commission report last year.
"It's now vital that political parties in Scotland present a clear vision for how they intend to ensure these new powers can grow our economy.
"As a centre-right politician, you won't be surprised to learn that I want to make the case for a competitive tax regime.
"My core principle is simply that taxes should not be higher in Scotland than elsewhere in the United Kingdom.
"I know that many of my opponents – and I'm sure half of them will be giving me daggers right now – will passionately disagree with me on that one.
"I won't seek to press my case on that tonight but I would like to make one point which, I believe, applies to all politicians at Holyrood, myself included.
"It's this.
"Scotland doesn't exist in a vacuum."