The new logo (left) being used in some Starbucks outlets has caused offence
US coffee chain Starbucks has come under fire for a new logo that critics say is offensive and overly graphic.
The Resistance, a US-based Christian group, has called for a national boycott of the coffee-selling giant.
It says the chain's new logo has a naked woman on it with her legs "spread like a prostitute... The company might as well call themselves Slutbucks".
Starbucks says the image - based on a 16th century Norse design of a mermaid with two-tails - is not inappropriate.
Rather, the image is a more conservative version of the original Starbucks design, which hung above the chain's first store when it opened in Seattle's Pike Place Market in 1971.
It says the image - the longstanding logo for Pike Place bags of coffee - is appearing on some of its cups as part of a promotion, and will remain "for several weeks".
Howard Schultz, who bought Starbucks in 1982, described the emblem in his memoirs as "bare-breasted and Rubenesque; [it] was supposed to be as seductive as coffee itself".
Although its share price has plunged in recent years, Starbucks has 16,000 coffee shops in 44 countries worldwide, employing more than 170,000 staff.
The chain has just opened its first outlet in Argentina.
Based in San Diego, the Resistance claims to have more than 3,000 members across the US and has gained a reputation for espousing diverse conspiracy theories