Why are you leaving your job?/ Why did you leave your last job?

You need to craft you answer in positive way, no doubt you had a bad experience with last employer. You may say, I want to switch the sector, or want to move from there as I served them long. The promotional policy of organization is bit tough. There was no challenging role remain for me.

 

i see far more potentitial for my self in the market place as it is only you who can determine our own worth

Never speak ill of former employers in an interview.
If you do, the interviewer will assume you'll talk about him/her in the same way.
Talk about how you want something more challenging,a place where you have opportunities to develop your skills, etc. 
      You may also say that you felt the job your applying for is better suited to your goals.
Another answer might be travel.

to make more experience, so that i can utilised my skills and knowledge

Leaving my job for better salary and work conditions. 

I want to peruse my experience in deferent place analysis and polish my skills more.

I am leaving my current job due to a lack of oppertunity. The reason leaving my last job was I working for a Design consultant that worked on portal frame designs, sports stadiums, residential, retail and mixed use buildings when the financial crisis of 2007 hit. I was working on two projects and the other projects the company had on the books were suspended or cancelled. Like many people in the country at the time I was facing unemployment and fortunately got employment with Waterways Ireland.

Loss of trust and confidence in senior managers

Seeking new opportunities outside the country. Social economic environment is currently very difficult

Leaving jobs for better salary and make own bright future

There was no challenging role in my career