As a British-born Indian supporter of Ukip I should be proud that the party I joined at 18 has grown to challenge the Conservatives and Labour so strongly. In reality, however, the direction in which the party is going is terrifying: Ukip has descended into a form of racist populism that I cannot bring myself to vote for. This week I decided to leave the party and I will abstain from voting in the upcoming European elections. I urge other Ukip supporters to do the same.

My reasons for supporting Ukip stemmed from liberal ideas such as lower taxes, a smaller state, freedom of the individual, local referenda, and an immigration policy that offered fair and equal opportunities for everyone. There was none of this "they took our jobs" business in the party's youth wing when I joined three years ago. Ukip's immigration policy, to me, was all about equality for every nationality; it was about treating Europeans and people outside the EU equally. But the recent racism scandals suggest, it seems, that most other Ukip voters and members support the policy – and the party – for a very different reason.

Ukip poster: '26 million people in Europe are looking for work. And whose jobs are they after?' Photograph: Ukip/PA

The above poster epitomises where the party is going wrong. This anti-immigrant campaign undermines Ukip's claim not to be a racist party. They are turning the election into a game of "us" and "them". Well, I am with "them".

Having worked so hard to help Ukip rid themselves of their "racist" label and denying comparisons to the BNP, this direction of campaigning really isn't doing my former colleagues any favours. I understand that British politics in the 21st century has become a dirty game of populism, but Ukip is straying further and further from the policies that attracted so many of its original supporters, instead cynically pursuing ever more aggressive anti-immigrant rhetoric.

After preaching about "common sense" and standing up as the "people's party", it is ironic that previously fundamental policies like taxation and promoting a small state are being ignored in favour of going after the votes of those who think Lenny Henry "should emigrate to a black country". Ukip is exploiting the stupidity of ignorant anti-immigrant voters for electoral gain. While the party deliberately attracts the racist vote, I refuse to be associated with them.

I am the daughter of Indian nationals and strongly support immigration. According to the Adam Smith Institute, GDP could more than double with the free movement of labour. There's no denying immigration is a positive thing. Yet if I voted Ukip, how many of those voting with me would privately prefer that my parents and I were not citizens of this country?

Ukip is now constantly in the political spotlight, meaning it is easy for members and candidates to get tripped up. In order to convince society they are not racist they need to stop giving positions in the party to people with racist views. It is not good enough to say that these individuals just slipped through the net, time and time again. Yes, Ukip is still a relatively young party. No, that is not an excuse to allow racists to stand for election. Nor is it an excuse to exploit the ignorance in British society and indulge the racist vote by telling them "they'll take your jobs". Sorry Ukip, you've lost another vote.