Allan Boesak, the Western Cape premier candidate for Cope, has invited Helen Zille to join his party.

"Helen's intentions and her gravitas as a leader could have been a vehicle for true change, but she is in the wrong party," he said in a campaign speech the text of which was circulated on Tuesday.

"If Helen truly has the courage of her personal conviction, surely her political home is in Cope, and we will welcome her."

Speaking in Riversdale at the weekend, Boesak described the Democratic Alliance, which Zille leads as a mishmash of seventies liberals, conservative former National Party politicians and misled voters from marginalised communities.

"Helen Zille's intentions may be honourable," he said, "but she is weighed down by a party stuck in a dichotomy of rhetoric, a ball and chain hung between a rock and a hard place, an ideology spread thin between expectation of delivery and a reluctance to share."

After slamming the ANC for its failure to deliver to the people, Boesak said that Zille has also had the opportunity, in a DA-led city of Cape Town, to show South Africans the power of their promises.

"The result though, is a tale of two cities," he said, "where the DA falls into the ANC trap of taking care of their cadres first, those who continue to live in stark contrast with the majority of South Africans.

"The DA is no different from the ANC. Helen's forgotten Cape Town is clearly visible a mere fifteen minutes from the city bowl. Khayelitsha, Ravensmead, Mitchell's Plain, the list goes on.

"The irony is that these are also the ANC's forgotten people. So too in every township, in every shantytown and indeed, in every city. On the campaign trail, convenience blinds both parties to their failures, but promises abound."

Boesak also criticised Zille for wanting to increase the city rates.

"Now, Helen Zille's DA council wants to increase taxation across the board," he said, "ignoring differences in income ? digging deeper into the shallow pockets of a struggling citizen and reducing business bottom lines even further."

He concluded: "Let's get real for a second. There is no makeover that would ever change a leopard's spots. A predominantly white party with NNP baggage will never gain the trust of the majority of South Africans. It takes a party that provides a true alternative, a party like Cope, to stand up to the ANC and excel in opposition, and be ready to govern."