The new edition of the Good Beer Guide has slammed two of Britain's biggest regional brewers, criticising their "lust for growth".
In the introduction to the 2006 guide, published this week, beer guru and editor Roger Protz said Greene King and Wolverhampton and Dudley Breweries (W&DB) had left a "trail of destruction" following their recent series of acquisitions.
In July, Greene King bought Essex brewer Ridley's and controversially announced it would be closing the brewery. And only last month it announced a £187m deal to buy Scottish brewer Belhaven.
W&DB meanwhile purchased Jennings brewery in May and although it announced it would be keeping the Cockermouth brewery open, Mr Protz claims that it will only be a matter of time before the company shuts it down.
While admitting that both brewers had a commendable commitment to real ale - and that the Ridley's takeover had not been aggressive - Mr Protz wrote that the two companies' growing ambitions were a concern for the rest of the brewing industry: "The Good Beer Guide urges all regional brewers to stand firm against the insidious growth of the two new nationals."
But W&DB denied its aggressive acquisition strategy was harming the beer industry.
"Far from threatening the choice available, we are investing in ale brands in order to increase variety, improve quality and raise awareness of our beers among a wider audience," said Alistair Darby, managing director of W&DB Brands.
"We have recently invested £1.7m in Marston's Brewery," said a spokeswoman.
On a more positive note, Mr Protz acclaimed the impact of microbrewers on the beer market, saying the number of new breweries in comparison to previous years was much higher.
He wrote that the main driver behind this growth was improving consumer demand: "Beer lovers are tired of over-hyped national brands and avoid the bland apologies for lager like the plague. Beers with aroma and flavour are back in vogue."