David Cameron, Prime Minister of the UK, stated to support India so that it would get permanent representation on the United Nations (UN) Security Council. He said this policy in his manifest.
The Times of India: Cameron to support India's permanent representation in UN Security Council
Cameron is concerned about the upcoming general election. He emphasized the importance of the relationship between the UK and India, as well as progressing the free global trade.
The UK was the suzerain of India. Many people moved from India to the UK, and now there are many Indian restaurants in the UK. It is not surprising that Cameron is supportive of India.
UN Security Council is a committee that consist of five nations with permanent membership and some temporal representatives. The five are the US, the UK, France, Russia, and China. Germany, Japan, and other countries are also eager to be enrolled. But there has been no nations newly accepted since the establishment of the UN. The permanent representatives have the right of rejection in any agenda submitted in the council. If too many countries utilize the rejection, the council would be no more functional.
India is still developing in population and GDP. However, it has a territorial dispute with China. It is unlikely China will permit the entrance of India. I am not sure whether Cameron intends to control China through this deal. Anyway, it is difficult for India to win the membership, I think.