. "They focus on systems and standards and they have forgotten about learning."
Apprenticeships are proving a major political issue in the run-up to the general election, with pledges from all three main parties to increase numbers.
The Conservatives have vowed to create an extra 1 million apprenticeships during the next Parliament, with pound;300 million of funding redirected from the welfare budget.
Labour, meanwhile, has said it will create at least 80,000 high-quality training opportunities every year of the next Parliament, by making it standard practice for employers in the public and private sectors to offer apprenticeships.
The Liberal Democrats have also pledged to increase the number of apprenticeships, and to drive up the quality of provision.
But details about learning and the pedagogy behind apprenticeships were "worryingly thin on the ground" in the major parties' rhetoric, Professor Lucas said. "We are limited to sound bites about who can do more, the `arms race' we've been hearing about. Whichever political party or parties get in will have to do some careful thinking."
He added that there was a "fundamental need" to set ambitions higher when it came to work-based learning. "Rebranding in and of itself is not the answer. We must substantially alter the level of ambition attached to the word `apprenticeship' to be seen as the same as a degree.
"We should describe the desired outcomes [of apprenticeships] in more ambitious language; outcomes that aren't just skills but the resourcefulness and nous that higher-level apprentices need to show in the workplace."
Professor Lucas added: "Historically there was always something cultural about apprenticeships, about learning an ethic of excellence, with a morality attached to it. If we could start to get that back it could become a high-value alternative option."
Kirstie Donnelly, UK managing director at City amp; Guilds, backed Professor Lucas' calls for a greater focus on learning. "Politicians are making too many assumptions that apprenticeships are about learning and are focusing on the numbers instead of the learning," she said.
"The problem is that it isn't easy and they shy away from it. I would say to politicians, if you focus on the right aspects - the quality of the overall experience and the system needed to underpin that - then the numbers will follow."
A spokeswoman for the Department for Business, Innovation and Skills defended the government's approach to apprenticeships, and said the programme was underpinned by statutory standards to make sure that all apprenticeships offered "substantial" on- and off-the-job guided learning.
The spokeswoman said: "During this Parliament there have been more than 2.1 million apprenticeship starts and more than 1,000 employers are now involved in designing and delivering new, high-quality apprenticeships in professions ranging from policing to television production.
"But it's not just about the numbers. The government is reforming the apprenticeship system to drive up quality, ensuring that apprenticeships give young people the training and experience they need for a successful career."
Government statistics released last month show that the number of apprenticeships continues to rise. Provisional figures reveal that 147,500 people started an apprenticeship between August and October 2014, up from 130,300 in the same period the previous year.
Abolishing level 2? A `grave injustice'
Labour's proposals to scrap level 2 apprenticeships have been attacked by Unionlearn, the education arm of the Trades Union Congress (TUC).
Speaking at a conference held by the Association of Employment and Learning Providers (AELP) in London last week, Tom Wilson, director of Unionlearn, said the plans were "wrong" and would be a "grave injustice" to those who had achieved the qualification.
Afterwards, Mr Wilson told TES: "We absolutely support Labour's aspiration that level 3 apprenticeships should become the norm and everybody should progress to level 3, but it's not right to abolish level 2.
"There are a number of unions with thousands of members with level 2 qualifications who would be pretty upset that their members' qualifications could be devalued or abolished overnight."
He said he had already made his concerns clear to the party.
Stewart Segal, chief executive of the AELP, also insisted that Labour had "got it wrong".
But a Labour party spokesman said: "This is not about devaluing or abolishing good level 2 qualifications for young people, but in recent years low-level training for existing workers, many of them in their forties, fifties and sixties, has been rebranded as an apprenticeship to drive up the numbers. That's got to stop.
"That's why Labour will move towards a system where apprenticeships are level 3 qualifications or above, last at least two years and are focused on new job entrants."