My sympathies on losing your job. I'm sure its not an easy thing to deal with let alone the immigration issues it raises for you.
If you are on a work permit and you've now lost your job, presumably the company will inform the home office and your work permit will be cancelled and your current leave to remain curtailed. If this happens you'll get a letter from the Home Office indicating you have 28 days to leave the country and you will not be allowed reentry on your current visa after it has been curtailed.
Now some companies may not be that organised especially if their HR department has organisational change to deal with so the may not do it (or may not do it straight away).
If they don't cancel it and you re-enter the country on this visa, when the immigration officer asks you if you're still employed by this company you'd either tell the truth (in which case your entry may be denied) or you'll lie (not recommended and if it was subsequently found out it could have serious consiquences for visas you subsequently get).
W.r.t. ILR requirements, bear in mind the government is planning a new naturalisation/immigration regime to go live late next year so its uncertain what the exact requirements will be in the future. We should know more in January when the full legislation is put before parliament.
As it stands today, the requirements on absenses abroad are ill-defined and largely at the discretion of the case worker / their managers. The maximum number of days abroad over 5 years seems to float between 6 months and 225 days from reading various cases on this forum. Weekends during those absences may or may not be included as may or may not be the day of departure and return. A common theme across most of the cases I've read suggests absences of greater than 90 days really will scupper any chance of ILR.
You may want to read the current Set(O) form (for employment-based ILR applications) as it states the evidence you need to provide depending on your leave to remain. For work permit holders it requires:
Recent document(s) from the employer named in your current work permit confirming that you are still needed and that that your employment with them is continuing.
Document(s) confirming that you have spent a continuous period of 5 years in the UK:
- either as a work permit holder throughout that period, or
- as a work permit holder most recently combined with previous permission as a work permit holder, highly skilled
migrant, self-employed lawyer, or writer, composer or artist.
Given your current situation, I believe it will be difficult to satisfy these requirements.
Your best bet, if you wish for your current LTR as a work permit holder to count towards ILR, is to apply as quickly as possible for a Tier 1 visa (if you qualify) or try to get a Tier 2 sponsorship. If that can all happen before your current leave is curtailed, you may be lucky.
Not the best news, I'm afraid.
We'll have a better idear if Tier 1 holders start applying for ILR and things come unstuck based on gaps in employment.