Civil rights lawyers are ramping up their fight to halt Occupy evictions around the country, in the face of concerted efforts by city officials to clear the streets of their encampments.

Throughout the country, local authorities are citing health and safety concerns and invoking obscure municipal codes as pretexts for clampdowns, according to the National Lawyers Guild. This week saw two of the largest occupations, in Los Angeles and Philadelphia, cleared, while the first and most symbolic occupation of Occupy Wall Street in New York, was cleared amid violent clashes between police and protesters in mid-November.

Meanwhile, activists from Occupy San Francisco have voted against an offer from the city to move to an alternate site, with some suspicious that the offer is a political tactic by the mayor to seem compassionate before an upcoming raid.

Lawyers have, at least temporarily, fought off evictions in Boston, Augusta, Maine and Nashville, Tennessee, citing first amendment rights to protest.

Mara Verheyden-Hilliard, the co-chair of the NLG Mass Defense Committee, said: "They claim there are these urgent health and safety reasons. Our experience is this is pretextual. The fact that they are having multiple conference points and discussions would suggest this is not an urgent local safety matter."

After reports on conference calls between mayors from different cities, the Police Executive Research Forum admitted conducting two conference calls to "allow police chiefs to compare notes" on the Occupy protests.

Verheyden-Hilliard said the basis behind the evictions were "illegal and pretextual" and said that NLG had hundreds of lawyers and law students across the country who would be quickly mobilised to fight them.

Lawyers have already won reprieves, in the form of temporary restraining orders, for activists in other cities. In Boston, a judge on Thursday upheld a temporary restraining order allowing them a reprieve until a decision on 15 December.

"These are just first amendment activities" said Verheyden-Hilliard "Why are they being treated like criminals? People camp out before a major movie screening or outside stores at Thanksgiving. The difference is that one group of people are engaged in a constitutionally protected and cherished activity. The others want a sale."

NLG lawyers were in court on Thursday to argue for the release of 300 activists who remained in custody after Tuesday night's eviction. Pressure on government officials has already lowered the bail set for them from $5,000 bail to $2,000.

Verheyden-Hilliard, who described their continued incarceration as an "an outrageous violation" said the LA example was further evidence that activists are being punished unjustly. She said: "The city is obliged to release people on these kind of misdemeanour charges without setting this kind of bail. The fact that they have kept them for so long is evidence that they are using criminal charges as a punitive measure against free speech activities."

Scores of occupations remain in towns and cities from Maine to Florida. They include: Washington DC; Buffalo, New York; West Palm Beach, Florida; Boise, Idaho; Louisville, Kentucky; Pocatello, Idaho; Pittsburgh; Des Moines, Iowa; Boston; Newhaven, Connecticut; Hartford, Connecticut and Rochester, New York.