Jim Wallace, the party's leader, and coalition Deputy First Minister, promised the commitment would make a difference for a generation. "These national tests deprive children of valuable learning time, break the flow of classroom teaching, create additional work for teachers, confuse parents and drain valuable resources in schools. And, in the end, the tests simply confirm what teachers already know," Mr Wallace said.
He added: "The tests are not operated to a uniform standard and there are claims that schools teach to the test. As a legacy from a previous political dogma, it is time for these tests to be scrapped. They would be replaced by more meaningful ways of ensuring standards in our primary and secondary schools are maintained and improved."
Parents would be consulted on the type of information they would find useful and the inspectorate would continue to monitor standards and progress.
Mr Wallace's fellow Liberal Democrat, Nicol Stephen, Deputy Education Minister, has chaired the Scottish Executive's inquiry into assessment in the 5-14 curriculum and championed reform.
Ministers have already signalled their intention to abandon the tests which were hatched as a compromise during the Conservative administration of the early 1990s and have failed to deliver meaningful information on pupil progress.
Most authorities now use some form of more objective testing in primary and early secondary to assess pupil potential, in addition to the 5-14 tests.
Stirling, for example, discovered wide disparities in pupil performance, even in mathematics, when it used standardised tests alongside the national tests.
New national tests - as they are being dubbed - are based on the more reliable Assessment of Achievement Programme sampling techniques and were due to be announced last month but the plans have been shelved during the election campaign.