By Alison Smith BBC News education reporter

Academics dispute the salary statistics given by employers

"I believe I earn less than a tube driver and I have a degree, PhD and 10 years' experience," the psychology lecturer and Natfhe official at the University of Westminster says.

"I started at the bottom of a very low pay scale 10 years ago and have been paying catch-up ever since.

"I've been surprised at the level of anger there is, even among members who are not normally that active. People have just had enough."

She says younger staff are the ones who are suffering on low starting salaries, along with part-time lecturers who earn proportionately lower pay.

"You have to ask: 'Is a PhD going to be attractive, coming into a low-paid career when you are trying to pay off debt?'"

"Nobody comes into this for the money, but it takes a long time to train for this."

Keep waiting

Tania Burchardt, a senior research fellow in social policy at the London School of Economics, agrees.

"Compared to people in the private sector or elsewhere in the public sector who have a number of years of training and experience, we are significantly under-paid," she says.

There is new money to increase pay, striking lecturers say

Unions have been very sympathetic to the employers' argument that they have not had enough money from government to fund wage increases above inflation, she says.

But now the time has come to invest in staff.

She rejects the suggestion that unions should wait until the trickle down effect of variable top-up fees, introduced this September, has been felt. Academics can no longer keep waiting, she says.

And she will be participating in the "action short of a strike" which the unions have called for.

This includes the boycotting of marking essays and exams.

"We are still teaching and transferring knowledge. We are ensuring that the students still get their education."

The presence on the picket line at LSE is pretty small. Lecturers who are there say they believe that in practice, many will stay at home.

Disruption

Kimberley, a University of Westminster student, is not feeling sympathetic to the strikers.

She has made the trip to the campus in Regent Street from her home in north London to find her English class cancelled.

"The tutor didn't even email me to tell me and I'm a bit annoyed," she said.

"From what I've heard about the action, I don't think they should be striking at all. I don't think their reasons over pay sound that justified," she said.

But Moira Macguire displays a petition signed by "hundreds" of students, and says they are mainly very supportive of their action.

Feelings and grudges seem to run much deeper than the surface disagreement about pay.

This action is borne out of a long-standing feeling that the status of an academic has been slowly eroded over the years.

It is also about where the profession will be in years to come - about the increase in managerial responsibilities and the decline in academic autonomy. If the role is going to change, rewards need to follow, academics feel.

Moira Macguire [left] says the students have shown their support

Jill Jones, Natfhe branch co-ordinator at the University of Westminster, says the days where lecturers' salaries were on a par with that of doctors and MPs are long gone.

She says the government has acknowledged that academics' pay has fallen behind other professions by around 40% - and the added income for next year must lead to a pay increase.

She cannot guarantee that no student's assessment and exams will be disrupted by action short of a strike.

But any delay in marking will not damage students' prospects irreparably, she says, as marking will happen "when we have settled on pay".

"If employers really cared about students they would have made us an offer, but we haven't received a single offer in the six months since we put in our pay claim," she said.

'Reasonable wage'

Two other female first-year LSE students, who do not want to give their names, say any lectures missed today have been rescheduled, so the action has not caused them much disruption.

They seem more concerned about the prospect of a marking boycott, pointing out that they are paying for their tuition.

But they do not seem very aware of how much their tutors earn.

The University and Colleges Employers Association says that the average LSE academic earns �40,806.

The pair think this is a reasonable wage in London.

But Tania Burchardt does not think this sounds like a plausible figure.