Job in Singapore - employer says that somehow this opportunity is not going to work

I have been offered a job in Singapore. I Applied EPass and it got approved too. I was supposed to travel a week before. My employer says that somehow this opportunity is not going to work out (he said that his client is not willing to go with my profile as of now. I have been technically interviewed by the same client and got positive feedback from the client). I'm not sure whether my employer is telling truth or not. Can I file a legal case against him?

Please advice