Apple's rumoured iPad mini, which is expected to be unveiled on Tuesday, could be bad news for competition such as Amazon, Google and Samsung, an analyst has said.

Apple Insider reports that Sterne Agee analyst Shaw Wu has said that Apple's smaller iPad will be "the competition's worst nightmare," even if it doesn't sell at a low price point.

Wu believes that Apple could sell its iPad mini for $350 and still beat Google and Amazon's $199 tablets. Wu believes the iPad mini will sell for $299 or $349.

A second analyst has said that the iPad mini could give Apple a three to five year advantage over competitors, reports Apple Insider.

Ming-Chi Kuo, an analyst with KGI Securities, told investors in a note on Friday that the iPad mini would cause new demand for smaller tablets. Kuo thinks that Apple has much to gain by launching a tablet that falls between the iPhone and iPad.

Kuo thinks that Apple is "most concerned about competing ecosystems from Amazon and Android," the report says. The analyst believes Apple's smaller iPad will be priced from $300.

The iPad mini is likely to be launched today at Apple's official event, possibly alongside other new products including a 13in Retina MacBook Pro and a new iMac lineup.