One of the key issues debated in each of the last three Leaders' debates has been immigration.  It's been cited as the reason for unemployment, it's been mentioned in relation to public expenditure, and with the support of the fascist BNP, it's been pushed into the media spotlight.

I find the main political parties' views on immigration extremely old fashioned and backward thinking.
Britain currently finds itself in a rather large amount of debt.  With the level of national debt increasing month on month, even now, a substantial cut in public expenditure is required; either that or an unprecedented increase in our productivity and profitability.  Unfortunately the UK has had its time. 
The UK economy is shrinking, the standard of our Universities has decreased year on year.  The initial aim of allowing more people access to Higher Education was admirable - allowing people from poor backgrounds the opportunities they've never had before - has been usurped by a new era of middle-class wasters who's only achievement at University was to come first in a drinking contest.  Whilst I don't decry such activities, there are Universities with a 'work hard, play hard' attitude, whilst there are others where lectures are a side-show to the main social events.
People with that as their aim don't deserve to be in University.  How can we seriously expect to have well performing Universities if we don't have a minimum standard of attainment to access them? It's not a hard position for me to defend, as by my own judgement I shouldn't have been given the opportunity to attend University.  It's not the institution that sets the standard - they had plenty of resource - it was the motivation of the students that attended.  The majority were attending purely as a 'rite of passage' as a "middle-class" citizen.
I remember when I passed my Grade 3 piano certificate; knowing how much effort I had to put into it.  I was immensely proud of the achievement, because I'd failed the exam once and had to resit.  This didn't phase me and make me feel like a failure; it motivated me to achieve, and when I did achieve I knew that I'd surpassed a certain standard.  I'd improved myself, and made progress.
I attended an institution where the lectures on 'Balance Sheets' were invariably interrupted by someone complaining that they were confused about how to use their calculator, where identical 'exercises' were carried out each week (with small changes to the hypothetical scenario), and where after graduating, I felt as though the qualification wasn't worth the paper it was written on.  Absolutely nothing I did at University expanded the academic knowledge of Britain, and very few of those that were graduating had gained enough 'training' (as opposed to teaching) to become competitive in the jobs market.
So, back to immigration.
What makes us think that we deserve to close our borders and allow people, like the above, to get first choice access to jobs in the UK, when there are people with a much greater work ethic and need.  I'm not advocating that we don't keep jobs for people in the UK, but our UK economy is shrinking.  In the same way that the big Record Labels and Film Companies need to adjust and change to the new digital economy - the UK economy needs to face it's new position in the world economy.  We can become 'enablers' to other economies and help them grow - rather than becoming proud and trying to gain our status as a global power.  
Investment, both with finance and time, in foreign economies will help fix the balance between the developing and developed world.  When I was in India, I was working 10 hours a week doing simple Linux System Administration - for that same job in the local economy, my pay would have been less than 10% of what I was earning.  This isn't just an opportunity for the politicians to create jobs for people in the UK, but people all over the world.
Healthcare is one of the main reasons cited for people coming to the UK, with the NHS touted as the sole attraction.  However, one of the saddest parts of the whole saga is that so many of the foreign Doctors in the NHS are here at the expense of their own communities back home.  The 'brain drain' away from developing nations does them little favour for their economies.  Allowing 'skilled workers' into the UK, whilst blocking 'unskilled labour' is blocking the development of other economies.
Unfortunately it's not that simple.  I don't think I have an answer.  Skilled workers will come to the UK in order to send money back to their families.  Sustaining an economy using money, rather than jobs is analogous to the old adage from Oxfam:
"Give a man a fish, and he'll eat for a day.  Give him a fishing rod and he'll eat for life"
It's pretty hard to bite the hand that feeds you, and harder still to not be labelled a hypocrite for doing so - but I believe it's something we need to do, both as a moral standpoint and in order to regain the respect of the global community,