Gauteng Premier Mbhazima Shilowa resigned on Monday out of loyalty to ousted president Thabo Mbeki and because he did not want to be "in constant battles" with the ANC leadership.

"I am resigning due to my convictions that while the ANC has the right to recall any of its deployed cadres, the decision needs to be based on solid facts, be fair and just.

"I also did not feel that I will be able to, with conviction, publicly explain or defend the NEC's decision on comrade Thabo Mbeki," Shilowa told reporters in Johannesburg.

"You stand by your own if you think they've been wrongly dealt with. I'm doing no more than that," he added.

He denied that he had been "pushed" to resign but said he was doing it out of principle.

"It is a known fact that I hold strong views on the manner of his dismissal and to pretend otherwise would be disingenuous," Shilowa said, referring to the ANC National Executive Committee's decision to remove Mbeki from office.

"I acknowledge and respect the ANC's rights to recall any of its deployed cadres. I am, however, of the view that there was no cogent reason for doing so."

ANC spokesman Nkenke Kekana confirmed that Shilowa had resigned "entirely on his own".

Shilowa said he informed the ANC provincial leadership of his intention to resign "immediately" after the NEC had announced the decision to remove Mbeki.

"It was agreed that while I reserve the right to do so; it would be prudent if I were to take time to reflect on this matter and not make the decision in haste...

"I did not want to be influenced by anyone."

Asked if he knew of any other premiers resigning, Shilowa replied: "This is not a collective resignation. It's mine and mine alone... I've done a lot of soul searching. I didn't want to sit down tomorrow and think, my goodness, couldn't you have waited."

But he said he came to the conclusion that he agreed with the "issues and values" Mbeki stood for and that he could not perform his duties while constantly disagreeing with the ANC leadership.

"I think I would not be able to fulfil the duties, [what if] they'd say to you, 'you've got to toe the line' and you couldn't? I think it's better to leave with my principles intact..

"I would have preferred to finish [his office term] but I think it's in the best interest for everyone to leave. You don't want to be in constant battles with the party."

He said he stood by his widely publicised interview in the Mail and Guardian newspaper that Judge Chris Nicholson's ruling was not based on fact.

Nicholson's ruling that Mbeki may have interfered in the decision to prosecute ruling party leader Jacob Zuma, led to Mbeki's ousting.

But his criticism of the ANC decision to remove Mbeki did not mean he did not have confidence in newly elected President Kgalema Motlanthe.

"I am known to speak out. If I had no confidence I would have said so."

Shilowa denied rumours that he was starting or would be part of a new political party.

"I know of no group who is starting another new party. I cannot be party to something I do not know," Shilowa said.

He said his resignation was likely to take effect at the end of October and that his successor would be under no obligation to appoint the same MECs he had appointed.

"I leave feeling well.... I do have a handkerchief... [but] the anticipated tear let me down, it refused to come," said Shilowa.

The Freedom Front Plus said his resignation indicated that the cracks in the ANC were becoming more clearly visible.

"Shilowa is merely another victim of the change of government which is taking place within the ANC. The tension in the ANC is good news for democracy in South Africa," said Jaco Mulder, FF Plus leader in Gauteng.

Earlier, the Democratic Alliance said Shilowa was being distracted from doing his job by in-fighting in the ANC.

Gauteng DA leader Jack Bloom said he regretted Shilowa's resignation and worried about the effect this would have on service delivery.

"I also worry about who will succeed him. Shilowa is head and shoulders above everybody else in his cabinet, many of whom let him down with their inefficiency and failure to crack down on corruption."

Bloom charged that the "front runner" for the post, finance MEC Paul Mashatile, had not run his department well.

It was the only one to get a qualified audit by the auditor-general last year, and he had been unable to clean up the Gauteng Shared Services Centre, which Bloom described as "controversy-plagued".

"My fear is that service delivery will suffer because of the infighting in the ANC."

He said community safety MEC Firoz Cachalia and local government MEC Dorothy Mahlangu may also be vulnerable, and go.