OPINION: the speech explaining why you have been fired

When you say things like "demotivated" or "I started not giving my best", I hear "If things don't go my way, I'm going to give up" -- that's not a good thing.  You really want to try and put a positive spin on the situation.

That being said, it sounds like your proposed explanation is really what happened, and let me tell you, it doesn't reflect well on you.  Yes, your company did what sounds like a pretty bone-headed reorg, but you got demotivated all by yourself.  *You* chose to react badly to the situation, and by the sound of it you didn't leave the company much choice *but* to fire you.  Did you think that by not giving your best that the company would realise the error of its ways and give you a big pay rise, or re-hire all the managers?

I'd suggest that before you head off to any interviews, you think about what happened -- both the circumstances and your reaction to them, and why that wasn't a good way to handle things.  Consider how you could have handled the situation more professionally (talking to your boss about the change in responsibilities would have been a good start).  Once you've got that sorted out, you can rethink how you'll explain why you got fired in terms of what you've learnt, not the company's actions.  Recall that the "why I got fired" speech ends with "I've learnt a lot", and you want to be able to expand on that in the interview if asked.

Saying "I got fired because I wasn't giving my best effort ," is going demotivate hiring managers.

It sounds like you got a bad deal, but  maybe that was the best company could offer given the circumstances. Regardless, you need to taking responsibility for how you handled it. You are trying to deflect the blame for your dismissal to your prior employer to justify your reaction. It is unlikely a prospective employer will see it that way. 

You can bet why you left last job will be asked and a lot of attention paid to the answer. Your best bet is complete candor, own it completely. Something like -- I messed up, I was in a difficult situation and handled it poorly. Took me a bit to put things in proper perspective, but here is what I learned ...  

Interviews are sales situation, being upfront would show you have confidence in the product you are selling (yourself) and provides you an opportunity to look forward positively.  

 Hi Thais,

I agree with the above comments.

I agree one should always act professionally and give ones best regardless of the circumstances or take the decision to leave if not in agreement with the conditions. I can also understand sometimes that is easier said than done.  

I am Brazilian, and I lived in Australia for 6 years. First time I heard in Australia a friend was fired, other friends comments were:  "That is good, he can get something better."  I was so impressed by that comment I never forgot.  That was a completely different perspective from what I had grown up with and experienced in Brazil which was the fear of being fired or even the fear of giving up a "good" job for the uncertainty of the market.  That uncertainty, that fear, makes us believe we are much less in control than we really are.  Then there is blame and resentment.  On the other hand there are companies that exploit the employees just because they can, because of that fear.

Although I can understand the circumstances that lead to the situation you were in, I do agree with the above comments that you need to reflect on what happened and get out of the victim position of having been exploited.  Because the managers from the company you will be interviewing are the company and most will take the position of the company not yours (and the truth is employers and employees should be on the same, not opposite sides) and what they will see is exactly what MattPalmer said: somebody that don't give his/her best, or doesn't have enough patience.

On your answer though I wouldn't start with "I messed up."  The truth is probably both you and the company have messed it up.  I don't know but think most interviewers may hear that "I messed up" and then not hear the whole story and what you learned from it. I would say something like:  "The company was going through an restructuring process.  Managers were laid off, and the coordinators, which I was one of them, assumed the managerial tasks. 

I was expecting and increase in salary due to the increase in responsibilities and that never came. I became frustrated, the work environment was not good (if that is true and it usually is when there is restructuring and significant lay offs), and eventually my performance was affected. I wasn't performing as well as I should have been performing. There wasnt a good match anymore after all the restructuring, between me and the company, and I my boss realized that before I did, I was fired. What I learn from this situation is: - say what you have learned and how you would handle the same situation different next time.

Some things you may add and which may make a difference in the eyes of the interviewer.

How long were you at the leading coordinator role acting as a manager? Did you actually perform well at that role for a while, before your performance worsen? When the managers were laid off, who became your boss? Did you have someone available you could discuss yours vs their expectations?
How you tell about what has happened also depend on what role you are applying for. Are you applying for a managerial position?
Also, it is not easy to shift from a individual contributor or coordinator to a manager position, much less when it is non-official. Were you purposely not giving your best or perhaps you were not fully prepared for that role? I would actually accept better someone accepting and recognizing their difficulties and weakness in becoming a manager than I would of someone not giving their best. My guess is there was probably a bit of both?
Really, there is no problem in it as long as you can learn from it and show that you have learn.
Good luck! And someday you will look back and say to yourself: "Good thing I was fired so I was forced to look for something better."

I agree totally with the others. With all due respect, if I got this answer, there is no way I would hire you. Definately need to spend some time working on a better description.

Also, although it may happen, I have never heard of a layoff/work dumping scenario where the people left actually got raises. It's not fair, I totally agree. I just wonder that it doesn't seem to be common so perhaps it was unrealistic to expect it. I'm interested to hear what others have to say about pay for the people left behind after a massive layoff as you described.

Layoffs occur for two reasons: the position(s) being laid off are redundant (hence no extra work should land on anyone else), or because of financial problems.  If the former, there's no reason for a payrise, and for the latter, the company let people go because it ran out of money, so there won't be any spare cash around for payrises for the survivors.

In my opinion, if there's a payrise to compensate for extra work *immediately* after a layoff, you're being lied to -- it wasn't a layoff, it was a culling of dead wood disguised as a layoff.  There may well be a payrise down the line (say, 6 months to a couple of years), probably because the layoff did its job, saved the company, and it was able to rise from the ashes, and the payrise is then put in to compensate for the additional duties now that the company is out of the financial woods.