I just did a quick look through official EU documents and the earliest mention I can find of the phrase "1967 borders" is this 2002 document, which was quickly followed by a host of others with the same wrong formulation.
It is astonishing that Israel apparently never pushed back on the EU to change that incorrect language.
But beyond that, it is notable to see how the EU's language has, over time, become more strident against Israel and more pro-Palestinian.
From the June 1997 Presidency Statement:
The foundations of peace are widely known : the right of all States and peoples in the region to live in peace within safe, recognized borders; respect for the legitimate aspiration of the Palestinian people to decide their own future; the exchange of land for peace; the non-acceptability of the annexation of territory by force; respect for human rights; the rejection of terrorism of all kinds; good relations between neighbours; and compliance with existing agreements and the rejection of counterproductive unilateral initiatives. In this context the Union recalls its opposition to settlements and attachment to security cooperation.
...We call on the people of Israel to recognize the right of the Palestinians to exercise self-determination, without excluding the option of a State. The creation of a viable and peaceful sovereign Palestinian entity is the best guarantee of Israel's security. At the same time we call upon the Palestinian people to reaffirm their commitment to the legitimate right of Israel to live within safe, recognized borders.
From the June 2002 Presidency Statement - as noted, the first time I can find a reference to "1967 borders."
The European Council strongly condemns all terrorist attacks against Israeli civilians. The peace process and the stability of the region cannot be hostage to terrorism. The fight against terrorism must go on; but so at the same time must the negotiation of a political solution.
A settlement can be achieved through negotiation, and only through negotiation. The objective is an end to the occupation and the early establishment of a democratic, viable, peaceful and sovereign State of Palestine, on the basis of the 1967 borders, if necessary with minor adjustments agreed by the parties. The end result should be two States living side by side within secure and recognised borders enjoying normal relations with their neighbours. In this context, a fair solution should be found to the complex issue of Jerusalem, and a just, viable and agreed solution to the problem of the Palestinian refugees.
The reform of the Palestinian Authority is essential. The European Council expects the Palestinian Authority to make good its commitment to security reform, early elections and political and administrative reform. The European Union reaffirms its willingness to continue to assist in these reforms.
Now compare those to this statement from the High Representative, November 2012, which no longer calls on the PA to have any responsibility - as if the PA has achieved the goals of democracy and transparency insisted upon ten years earlier:
The EU has repeatedly expressed its support and wish for Palestine to become a full member of the United Nations as part of a solution to the conflict. The EU has also consistently worked to advance the Palestinian Authority's state-building efforts under Prime Minister Fayyad. It will continue to do so. Recalling the Berlin Declaration of March 1999, the EU reiterates its readiness to recognize a Palestinian State when appropriate.
...It is important for all parties and actors involved to work towards a settlement of the conflict with renewed purpose and sense of urgency. The European Union recalls its well-known positions on intra-Palestinian reconciliation behind President Abbas, settlements and Israel’s security. The European Union calls on all parties to pursue actions conducive to an environment of confidence necessary to ensure meaningful negotiations and to refrain from actions that undermine the credibility of the process....
The EU reaffirms its position that clear parameters defining the basis for negotiations are key elements for a successful outcome, together with the avoiding of unilateral measures and acts on the ground which undermine confidence and the viability of the two-state solution. The European Union reaffirms that it will not recognise any changes to the pre-1967 borders including with regard to Jerusalem, other than those agreed by the parties...
Two weeks ago, from a joint statement with the GCC:
The Ministers reaffirmed their shared position that a just, comprehensive and lasting peace in the Middle East is vital for international peace and security, noting that such a solution must be based on UN Resolutions and the Arab Peace Initiative, leading to the establishment of an independent and sovereign Palestinian State on the territory occupied since 1967. ...
The Ministers reaffirmed their position not to recognize any changes to the pre-1967 borders other than those agreed by both parties including with regard to Jerusalem. They stressed their common position that Israeli settlements anywhere in the occupied Palestinian territories are illegal under international law and constitute an obstacle to peace. In this regard, they called on Israel to immediately end all settlement activity in East Jerusalem and the rest of the West Bank, including natural growth, and to dismantle all outposts. The Ministers agreed on the need to continue to support Palestinian state-building efforts, both politically and financially.
I still do see some more recent documents that call for "secure and recognised borders" such as this one from January 2012 and this one from this month. But both those statements also enshrine the "Arab Peace Initiative" as one of the bases for peace.
The change in language over the years is unmistakable. Essentially the entire Palestinian Arab position has been adopted fully by the EU.
There is not even insistence to end Palestinian Arab incitement against Jews and Israel, nothing about Hamas (and some Fatah) terrorism, nothing condemning Abbas' embrace of stone throwing and firebombs as "peaceful resistance" - nothing.
This represents a great failure on the part of Israel's diplomats.