More than 1,200 people are expected to attend the mass lobby, organised by the Campaign for Real Ale (CAMRA), and supported by the Publican’s Morning Advertiser.
The event is the next step for the campaign, after an e-petition on the topic smashed the 100,000-signature target.
It led to a three-hour debate in the House, with MPs voting unanimously for a review of the escalator.
Griffiths, who is chairman of the All-Party Parliamentary Beer Group, told CAMRA members, licensees and brewers: “It's been brilliant to see you here today. We are here because we love beer and we love pubs. We recognise the importance of the great British pub.
“We have got an important opportunity today. The beer duty escalator is crippling the industry and we have got to get the message across to scrap it. We've come to the edge of the cliff. It's important to convince the Government about the need to scrap the escalator.
"The only person in support of the escalator (during the debate in Parliament) was the minister (Sajid Javid). We have to continue the pressure on Government, and make sure that they recognise that drinkers want action too."
Licensee Dawn Hopkins of the Rose in Norwich, has challenged MPs about duty increases, including former treasury minister Chloe Smith.
She said: “I think it is very important to show your MP the depth of feeling about it (the escalator), and how detrimental the beer duty escalator is.
"The whole pub industry is suffering and there is a recession. We get an extra tax every year that we have to pass on to our customers. If we don't, this is why pubs are closing. Personally I believe, if we can be more competitive and get more people through the doors then we can begin to stem the tide of pub closures.
"They (MPs) have too many excuses that they are helping pubs but they really aren't.”
Anita Adams, who runs the Maltings and Golden Slipper in York, added: “I think that the MPs actually need to do their homework. They are very lazy. They don't actually talk to the people who are providing the golden eggs to this goose, or were. Perhaps they think somebody else is now. They need to not only talk to us, but to listen."
Alan Pickersgill of the Crown in Uppingham, Rutland, said: "I'm here today to try and persuade my MP Alan Duncan to save the pub. Lots of industries have been given a tax break but there is a relentless barrage of tax for the pub trade.
"We had a poor response from the Government after the debate, so now it’s time to take direct action.”
John Dragun, head brewer of Robin Hood Brewery in Sherwood, Nottingham, is also at the event.
"We are taking the message of save the brewing industry, save our pubs, and save jobs,” he said.
"We are dedicated drinkers and have been for quite a long time - I am supporting industry, and I am supporting jobs."