Finance is a very important part of a pressure group it is nearly impossible to sustain a pressure group of any significant size without ample finances, the larger a pressure group often the more cash donors are able to support the party. A larger pressure group also creates more connections and networks to people that may be in perhaps a position of power to help influence others to the cause. Taking this into account if a party is large however isn’t receiving ample financial support the success of the pressure party will be greatly held back as it cannot pressure government without various legal & media campaigns - despite this large finances aren’t essential to play to the media. Fathers for Justice have caught the attention of the media on several occasions by doing various stunts such as climbing on top of the House of Commons.
Whether a pressure group is an insider or an outsider is also very important, being an insider party is rather advantageous if the party is reliant on influencing legislation. For example Charter 88 wanted major constitutional reform and targeted various Labour Mps, this lead to it being on the 1997 labour manifesto, being an insider can lead to more direct action, something large membership base could be beneficial for due to the amount of connections people may have.
Pressure groups with large support from celebrities are also more successful as the image of a celebrity can easily make a cause more ‘trendy’. This can be directly link to the size of membership because people are more likely to join, however this does not necessarily mean the pressure group will be successful. That is dependent on various other variables including the cause itself. An example of this is the IRA, prior to and motives to the terror attack were politically motivated and the origin of the IRA is a pressure group that resulted to illegal action.
Another variable which can influence success is how united a pressure group or niche of pressure group is, if similar pressure groups are often conflicting with one another the likelihood of influencing government is low. An example of this is teachers unions; there are several teachers unions which have similar and opposing views which can make it difficult for a transparent in relation to a cause to emerge. Opposing views occur on petty issues such as phone confiscation all the way to the 2012 strikes on public sector pensions.
The key to success does partially rely on its membership base, purely due to the fact that the membership base is where the power lies, the members generally have the finance and connections to implement change and influence others around them. However the membership base can only do so much, other factors can affect success such as the cause itself and the ability to gain media attention